Design of Nano Materials and Novel Functions
Strategy for nanotechnology research at the Centre for Materials Science and Nanotechnology (SMN)
Priority is given to five areas:
catalysis in nano containers and on nanoparticles;
design of nano structures;
investigations of functional surfaces;
nano devices / nano sensors,
Nanotechnology projects at SMN should bring genuinely new knowledge, materials or technology owing to the nanometer-size dimension of the material or system. Activities will focus on fields where the Centre holds top level research on functional materials; synthesis of nanostructured materials; catalysts and adsorbents; semiconductors and photovoltaics; ionics and superconductors. The extension into the nano-domain should be targeted as also to bring important advances in the application oriented activities; energy technology; oil, gas and environmental technology; information and communication technology. SMN will stimulate to crossdisciplinary projects and combination of theory and experiments.
Within the prioritized areas, collaboration with regional (FFI, IFE, SINTEF), national (FUNMAT partners) and international partners will lead to scientific and technological opportunities emerging from complementary strengths. SMN hosts a complex research infrastructure, however, just partly directed towards nanotechnology. In order to secure methodological expertise, adequate technical assistance and optimum operation, dedicated funds are required. Partner institutions should be invited to establish means to run and share expensive and complex infrastructure. Basis funding is required for the MiNa-lab at SMN with respect to Micro- and Nanotechnolgy. The proposed activities will further require some minimum investments. At a next stage, where robust nanotechnology activities are to be established in one or more of the now prioritized areas, significant costs related to laboratories and instrumentation must be expected.
SMN will establish a broad network on nanotechnology for activities at UiO and nearby institutions, in particular related to soft materials, biocompatible materials and life sciences. SMN will open its infrastructure towards possible broad collaboration projects in these areas. The opportunities are considered as major also in these non-core fields.
Objectives: Rational design of new and improved catalysts and adsorbents based on fundamental insight to reaction mechanisms
Objectives: Control of morphology and size of nanoparticles and design of multilayered thin films as basis for materials with novel functions.
Objectives: Ability to control and monitor surface structure and surface properties for selected materials and components.
The Centre for Materials Science and Nanotechnology (SMN) at the University of Oslo, aims at being an internationally well recognised centre housing excellent scientific quality, adept at interdisciplinary collaboration. The Centre emphasizes combinations of experimental and theoretical work, at professionally run laboratories containing the utmost in equipment. Its basic research will frequently have aspects of applicability; the purpose being – in addition to frontier science – to provide a competence basis for innovation of materials, components and concepts with industrial viability and thus contribute to future value creation in Norway. In this respect the Centre will collaborate closely with relevant research institutes, communities and industry to help bringing ideas from high quality basic research towards innovation.
The research at SMN is best described in a matrix, where skills in functional materials, nanotechnology and microtechnology cross prioritized activities within materials/components for energy technology, for oil, gas and environmental technology and ICT – all based on high quality in basic research.
The SMN research priorities fall into the mentioned matrix. Some fields are given particular attention and offers excellent possibility for national and international collaboration:
Nanotechnology comprises techniques for synthesis and processing, including manipulation and assembly using natures own building blocks for intelligent design of functional materials, components and systems featuring attractive qualities and novel functions. A crucial aspect is that dimensions and tolerances from some 1 to 100 nanometres play a decisive role. The term nanotechnology should be avoided used for well known research fields in a new wrapping.
Nanotechnology is today recognized as a strategically important field of scientific research with potential for inducing radical changes to disciplines and technologies. Nanotechnology is likely to have major impact on core activities at SMN; research related to future technologies in the energy, oil, gas, environmental and ICT areas. Nanotechnology is interdisciplinary, embracing physics, chemistry, molecular biology, medicine, electronics and ICT.
In the coming strategic plan for nanotechnology at the University of Oslo for 2005 – 2010, it is suggested that SMN should be the central research body at the University within nanotechnology. Further it is suggested that SMN develops an adequate laboratory infrastructure that opens up for nanotechnology research projects and broad collaboration with other groups at UiO and in the Oslo area.
The following group has on mandate of the SMN board made strategic recommendations with respect to SMN priorities in the nanotechnology area (mandate is enclosed in appendix 2):
Prof. Helmer Fjellvåg, leader of SMN,
Prof. Poul Norby,
Prof. Bengt G. Svensson,
Prof. Yuri Galperin and
Mona Moengen, secretary.
According to the mandate, the group has held discussion meetings with Institute for energy technology (IFE), the Defense research establishment (FFI) and SINTEF and invited these institutions to develop and describe plans for possible collaboration with SMN. The group has furthermore held discussion meetings with leading researchers in soft materials science and life sciences at UiO. Research on possible interfaces is described in the document. This strategy document has furthermore been discussed with scientific personnel connected with the Centre. The recommendations were adopted by the SMN board on April 19th, 2005.
"Taking into account the Norwegian research and the international research competition the panel strongly supports the establishment of a research network by the FunMat@UiO on nanoscience and nanotechnology. This is due to an internationally renowned expertise at UiO, which can be combined in a synergistic way to promote nano sciences as a leading research area and focus at least in the early part of the 21st century."
It was furthermore advised to concentrate the effort:
"We are convinced that strong collaboration between research groups at UiO can push forward research and technology in Norway to the international forefront especially in following research areas:
catalysis in nano containers and on nanoparticles;
design of nano structures;
investigations of functional surfaces;
nano devices / nano sensors.
These may be gathered under a single topic, such as:
Design of Nano Materials and Novel Functions.”
Objectives: Rational design of new and improved catalysts and adsorbents based on fundamental insight to reaction mechanisms
Rational design of new and improved catalysts and adsorbents based on fundamental insight to reaction mechanisms
Introduction and research vision
Catalytic materials and adsorbents are well suited for crossdisciplinary research at SMN. This is furthermore in line with the recommendation of the international advisory board of FUNMAT@UiO that the initial phase of strengthening nanotechnology at UiO should
Establish a coordinated activity on catalysis in nano-containers and on nano-particles (platform “synthesis and catalysis”) with experimental activities on synthesis and characterization of porous materials and substrates of nanoparticles with composition, morphology and size control. The activity should be supplemented by theoretical studies of electronic properties of nanoparticles and catalytic centers in nano-container materials”
The Gemini centre CATMAT, established between SINTEF and SMN in 2004 on “catalytic materials and adsorbents”, provides a research platform that builds on the individual strengths of the partners and that benefits from the synergy potential prevailing between fundamental and application oriented activities.
Heterogeneous catalysis is crucial for process industry, oil and gas conversion and e.g. environmental technology, and a major field internationally; yet many of todays catalysts have been developed by trial-and-error rather than by design. This fact reflects the extreme complexity of the field, with respect to surfaces and their structure, electronic and chemical properties, mechanical and thermal stability, etc. SMN will attack this complex and industrially important field by aiming at rational design based on mechanistic insight.
Catalysis, and to some extent adsorption, is tightly interwoven with process technology where surface properties of nanostructured inorganic or hybrid type materials, organic reactants and products, physical parameters, heat transfer, reactor design, etc are interrelated and optimized for conversion, selectivity and cost efficiency.
In order to fulfill the SMN research vision detailed insight and understanding of the catalyst (adsorbent) – from synthesis via activation and aimed reactions to product formation and catalyst (adsorbent) regeneration – is required. Detailed information on reaction mechanisms, active sites, the importance of local chemical, steric and electronic and redox aspects, intermediates, defects/impurities, exposed surfaces etc must be collected by a battery of methods. This will be achieved by “Combination of experimental and theoretical tools to gain insight in reaction mechanisms of catalysts and adsorbents”and “In-situ characterization of catalysts and adsorbents; from synthesis, via activiation to working conditions, deactivation and regeneration”.
From model systems to real catalysts and adsorbents
A. Nanocontainers; porous materials
Inner, tunable surfaces (with area up to many thousands m2/g) are found for microporous materials (zeotypes and metal organic framework structures (MOFs)), mesoporous materials, porous alumina and related support materials. SMN holds international leading competence in several niches of these fields. The vision of rational design will be implemented for microporous materials with respect to both catalysis and adsorption. The active sites are brought into the crystalline product via metal organic synthesis routes or by optimized solvothermal synthesis routes. Studies of the multivariate synthesis room will benefit from the expertise at SINTEF on parallel synthesis.
For microporous materials, the understanding of reaction mechanisms like now achieved for the carbon pool in methanol-to-olefin reactions will be a continued focus for subsequent design of active sites within nanocontainers.
Such design represents a major scientific challenge in particular for zeotype materials.
The insight in reaction mechanism should be the basis for optimizing new materials.
Priority will be given to:
o studies of reaction mechanisms for microporous materials (as catalysts and adsorbents), with particular focus on interrelation between active sites and intermediates that act as apart of the activated catalytic system,
o rational design of novel microporous materials (as catalysts and adsorbents),
o studies of reaction pathways for formation of microporous materials during solvothermal synthesis,
o in-situ studies of microporous materials at working conditions by proper combination of theoretical and experimental studies.
B. Nanoparticles; metal-support systems.
For metal/support systems finely dispersed metal particles or clusters with nanometer dimensions form typically active centers. A large number of industrial processes are based on this category of catalysts.
SMN will focus on its potential for high quality research within a few niches of this wide field. This will involve close integration of synthesis, mechanistic studies, surface characterization and modeling activities at SMN and collaboration with local/national partners. The competitiveness will benefit from synthesis activities on nanosized particles (with size and morphology control), on delamination of layered materials and ALCVD of finely dispersed metal components on porous substrates, nanoparticles or model substrates. In-situ studies will be extended to also comprise metal-support systems.
SMN will give priority to strengthening skills in synthesis of nanoparticles (and their modification) for use as model catalysts (for mechanistic studies, testing and modeling), strengthening activities in the in-situ field to also take up nanoparticles as catalysts and strengthening activities in mechanistic studies and activities on characterization and modeling.
Laboratories, tools, infrastructure
The focused activity on catalysis and adsorbents at SMN with ambitions of design at the nanometer level, requires adequate experimental infrastructure and integration along the whole line from synthesis, via advanced characterization to modeling. This calls for dedicated personnel. Close international collaboration with groups specialized in characterization and modeling, including access and experiments at large scale facilities (e.g. synchrotrons) is a prerequisite for a state-of-the-art activity that is likely to live up to the SMN vision.
The laboratories dedicated for
- materials synthesis
- mechanistic studies
must hold high quality and provide sufficient capacity. Improved facilities for in-situ studies of catalysts/reactions should be made available already within a short time frame. The battery of methods needed for site and surface characterization should be upgraded, and personnel resources should be available as to be able to collect services from methods of relevance for catalyst characterization. The laboratories for
- in-situ studies
- surface characterization
should be given special attention with respect to upgrading and optimized running.
Objectives: Control of morphology and size of nanoparticles and design of multilayered thin films as basis for materials with novel functions.
Introduction and research vision. Preparation of nanomaterials and nanostructures is one of the foundations in development of nanotechnology into devices. Two approaches for preparation of nanomaterials are known as top down and bottom up. The research plans presented here include mainly bottom up approaches using chemical means, while top down methods will be mainly used for post treatment, structuring and contacting.
In order to ensure research at a high international level, innovation and expertise are of the essence. We will in the concrete plans for preparation of nanomaterials and nanostructures build on our expertise in synthesis, structure and properties of oxide materials. We have long experience in synthesis of materials using solid state, hydrothermal and sol/gel methods, and have several projects on preparation of nanocrystals, nanostructures and nanocomposites. We have very good experience in preparation of thin films, especially using ALCVD and sol/gel methods, and have worked with preparation of high quality multilayered thin films with atomic layer control. Nanostructuring using e.g. e-beam lithography and ion beam implantation will be included in the research. Design and investigations of nanostructures is a good example of a research area where we will be able to take full advantage of the close collaboration between the research communities at Chemistry and Physics through SMN.
In addition to synthesis and bulk analysis of nanomaterials and nanostructures we intend to initiate electronic and magnetic measurements on single nanocrystals and nanotubes. Using electron beam lithography, contact points may be designed enabling measurement of electronic and electrical properties of single nanotubes or nanowires. Using a modified AFM method (magnetic force microscopy, MFM), magnetic properties of nanostructures will be probed.
Theoretical calculations of electronic and mechanic properties of nanostructures and nanomaterials will be a natural part of the research effort.
Nanocrystals and nanostructures. As dimensions of materials approach the nanometer range, significant effects on physical properties are observed. Therefore, synthesis of free-standing non-agglomerated monodisperse coherent nanocrystals with controlled morphology is of interest. Nanocrystals with anisotropic morphology, i.e. with one or two dimensions in the nanometer range (e.g. nanorods, nanowires and nanosheets) are of considerable interest, as their physical properties are strongly direction dependent. Likewise, synthesis of 0-dimensional nanocrystals in the form of free floating nanopowders (quantum dots) with controlled size and a narrow size distribution is of in connection with e.g. superparamagnetic particles, analysis of granular materials and as catalytic model materials.
TEM image of titanate nanotubes/nanoscrolls formed by hydrothermal conversion of anatase nanocrystals.
Other interesting types of nanostructures with high aspect ratio are nanotubular forms, such as nanotubes and nanoscrolls. Since the discovery of new carbon nanostructures there has been a large research effort worldwide in the field of carbon nanotubes. Both single-walled and multi-walled carbon nanotubes (SWCNT and MWCNT) have very interesting mechanical and electronic properties, and have great potential for various applications. There is, however, another group of nanotubes, which so far has not been extensively studied, but which has a very large potential for displaying new useful and revolutionary properties. It is possible to prepare some inorganic counterparts to the carbon structures, namely nanotubes and nanoscrolls of inorganic materials. Especially oxides would be of particular interest, as they have a significant potential for designing materials for technological application utilizing e.g. electronic, optical, magnetic and mechanical properties. For instance oxide nanotubes are may be utilized for sensor applications, as nanomagnets and for energy storage purpose.
Constraining nanostructures in two dimensions as thin films and nanostructured multilayers is crucial for developing devices based on nanotechnology. In addition, basic research on growth and physical properties of thin films are essential for the understanding of physical phenomena of multilayered films. Using ALCVD (Atomic Layer Chemical Vapour Deposition) it is possible to obtain a remarkable control of growth of e.g. thin films of complex oxides. As the method is based on atomic-layer by atomic-layer growth, it is possible to grow for instance epitaxial multilayers with control of the individual layer thicknesses on an atomic scale. The perspectives of this design of artificial 2-D heterostructures are dramatic; by careful design of the nanostructure of multilayer thin films it may be possible to tune electronic properties (e.g. band gap, for energy conversion), magnetic properties (for instance Giant and Collossal Magnetoresistance (GMR and CMR) materials) or optical properties. The superior growth control and low temperature conditions of the ALCVD method makes it very suitable for preparation of model systems and devices.
Ongoing research projects
We have ongoing research projects on synthesis of free-standing nanocrystals, where the focus is on morphology and size control. Many research projects involving ALCVD are initiated or planned involving collaboration within SMN. The thin film research within SMN is of high standard and is a very good example of cross-disciplinary research, where researchers from Chemistry and Physics have already worked together, for instance in experimental studies of interfaces in heterojunction solar cells. We have started preparation of some nanotube and nanoscroll materials of hydrogen titanate, and we will shortly start up a research program (1 postdoc. supported by NANOMAT) in preparation of inorganic nanotubes. This will be in collaboration with Reinhard Nesper, ETH, who is also professor II at the Department of Chemistry. Reinhard Nesper is one of the pioneers in the field of inorganic nanotubes, especially vanadium oxide nanotubes and nanoscrolls. An existing NANOMAT project (UiO, SINTEF, IFE) is aimed at preparing new nanostructured materials by self-organisation or by active reassembling of exfoliated layered materials. The exfoliated materials form stable colloidal dispersions. We intend to prepare new nanocomposites by reconstruction of exfoliated nanosheets, highly oriented coatings and materials with very large surface areas.
Introduction. The international advisory board of FUNMAT@UiO proposed “investigation of functional surfaces” to be given priority at UiO in a first stage of building up of dedicated activities in nanotechnology. For SMN this will include basic activities and competences at the Centre, primarily devoted to inorganic surfaces or inorganic-organic hybrid surfaces. The activity may in a broader context be seen along with activities on organic surfaces (polymers; drug delivery systems; biocompatible surfaces) at the faculties of Mathematics and Natural Sciences, of Medicine and of Dentistry.
Surfaces are all boundaries interfacing homogeneous or heterogeneous phases. In materials science and nanotechnology a surface is normally taken to be the interface between a solid and a gas or a solid and a liquid. While most surfaces in our surroundings are of structural nature, some are functional, i.e. they possess one or more chemical or physical (and useful) property in addition to just separating or containing phases. Surfaces are as such nanoscopic (ranging in effective thickness from atomic dimensions and upwards) depending on compositional and electromagnetic gradients. They represent a border zone that influences all transitions (transport, displacement) of atoms as well as electrons between the involved phases. The reactivity and to some extent also the stability of the materials is influenced by surface properties.
For many of the materials of tomorrow, in particular for nanomaterials, the importance of understanding and manipulating surfaces is accelerated, cf. materials/components for catalysis, separation, adsorption, sensoring, microsystems, bone repairing, etc. SMN has the ambition of being a major player in the Oslo area and in Norway in surface science. The basis for its ambitions is necessarily the underlying materials activities and available resources. In a first stage targeted activities on functional surfaces will be linked to other prioritized activities within nanotechnology; e.g. to thin films, nanoparticles, nanoporous materials, components with critical dimensions in the nano-range, catalysis and adsorption in nanocontainers. A central topic is knowledge on atomic structure and electronic properties of surface layers. Such knowledge is typically gained by combination of experimental and theoretical methods.
For SMN a minimum level of activities in surface science is considered as a must for having realistic visions on success in prioritized fields relying on surface properties, i.e. catalysis, adsorption, chemical sensors, nanotechnology, etc. The research vision can be formulated as
Objectives: Ability to control and monitor surface structure and surface properties for selected materials and components.
Objectives: Ability to control and monitor surface structure and surface properties for selected materials and components.
For nanoparticles and thin films, surfaces constitute an important and major materials part, and it is essential to understand the relation between synthesis and processing parameters and properties of surfaces and materials. Studies of the atomic arrangement in crystalline and amorphous phaser near internal interfaces and surfaces become thus essential in order to relate structural aspects, including electronic structure at the nanoscale, to transport properties, magnetic, optical, chemical and mechanical properties.
Many aspects of surfaces should be known as basis for monitoring surface properties:
Surface area, BET of micro/mesoporous materials; relate to crystal structure data and to modeling of available inner surfaces
Surface smoothness; reflectometry, AFM; relate to deposition methods, synthesis routes
Surface composition; XPS, UPS, RBS, SIMS, angle dependent XRD; relate to bulk situation, surface segregation, composition, synthesis procedure, chemical and physical properties, stability,
Surface structure; RHEED, LEED, XRD, SEXAFS, surface sensitive spectroscopy, comparison with theoretical predictions; surface reconstructions, effect of atmosphere (physisorption and chemisorption), relate to catalytic activity, use as basis for modeling
Domain structure; imaging techniques; HREM, MOI, MFM; relate to cooperative properties (electric, magnetic), to poling, yield (polarization, magnetization)
Surface electronic properties; XPS, UPS, electronic structure calculations; compare with bulk situation; effect of dopants and segregation; electrical characterization
Interface properties; TEM, electric characterization
Surface kinetics/activation; QIMS, SIMS; relate to oxygen exchange on membrane surfaces, TAP, SSITKA; relate to conversion efficiency of catalytically active surfaces
Surface probing with chemical methods.
Surface stability and thermodynamics; microcalorimetry
Since SMN has not yet established a dedicated surface science laboratory, probing of surface properties will involve collaboration between many groups/individuals.
Monitoring surfaces - reconstructions
SMN holds a number of techniques for depositing atoms and molecules on surfaces (ALCVD, MOCVD, sol-gel routes, incipient wetness), for growth of thin films (ALCVD, MOCVD, LPE, spin coating, magnetron sputtering) and for ion implantation into surface layers. Possibility of adding PECVD is being considered. The surfaces of porous materials are furthermore post functionalized by reactions with e.g. metal organic molecules.
Controlling growth dynamics
The growth dynamics of crystalline materials are controlled by the nucleation kinetics of new layers on the respective crystalline surfaces. This is achieved by addition of modifying agents that attach differently to the various crystalline planes. In this way the surfaces are functionalized and the habits of the crystals can be controlled. We have exemplified this by hydrothermal growth of nanocrystals of materials such as TiO2, Co3O4 and LaMnO3.
Thin film growth can be considered as a gas equivalent to precipitation from solutions. An analogous approach to the aqueous crystal growth mentioned above, applies also to growth from the gas phase. This enables us to gain control over such effects as film microstructure, texture, orientation and topography, viz. smoothness of the film surface. This requires competence on how to actively functionalize surfaces during growth, by addition of foreign molecules or by proper choice of precursors.
A coordinated research program on functional surfaces should be established at SMN. The ambitions should be revised during the first phase of the research initiative. At the onset, all relevant activities should be aimed integrated into the program, from probing of surface structure and surface dependent properties to monitoring of surfaces with aim to control their properties. The activity should be linked to research topics at SMN on materials for specific applications or materials with special physical/chemical properties. SMN can in a short term perspective not build up major activities in surface physics that require heavy equipment and competence far beyond the present resources. For such needs one should rather rely on national and international collaboration. For each of the following subfields, specific goals should be set in a 5 y perspective.
- competence in experimental determination of surface structure and reconstructions in various atmospheres (temperatures)
- development of theoretical skills to support experimental activities
- integration of characterization activities (chemical and physical methods)
- use synchrotron radiation to extend the possibilities of the home laboratory
- establish close link to prioritized activities in catalysis and adsorbents, and in other fields of nanotechnology at SMN
Surface monitoring and functionalization
- strengthen fundamental competence with goal to optimize deposition routes for transparent conducting oxides with emphasis on interfaces and thickness in relation to prioritized activities within semiconductor materials and photovoltaics
- improve fundamental competence with goal to optimize chemical and structural properties of membranes, catalyst and adsorbent surfaces for specific applications
- strengthen competence to modify surface properties of thin films by ion implantation techniques
- develop competence for modifying chemical, physical and mechanical properties of surfaces, e.g. by giving the surfaces strong affinity to certain targets, by changing tribological properties, by adding mechanical strength and corrosive protection, etc.
- develop integrated projects with microtechnology where dedicated surfaces may function as sensors in microsystem applications
- develop collaboration with activities in biomaterials at UiO and address questions on giving biocompatibility to surfaces and materials of interest in some of the prioritized projects at SMN
Self assembled monolayers
- develop competence for studies of structural arrangement in self-assemblies and ability to alter properties of the host material by means of self-assembled monolayers
- develop collaboration with activities in colloids and surface science at UiO
Surfaces of nanoparticles
- strengthen thermodynamical basis for understanding stability aspects of nanoparticles (surface/volume effects)
- develop tools to manipulate surfaces of nanoparticles and to characterize them
Laboratories, tools and infrastructure
In order for SMN to benefit from advanced tools and high competence in surface science, SMN should actively work along with the FUNMAT-partners to establish a national platform for surface science that links to Norwegian priorities in materials science and nanotechnology. SMN should take a leading role whenever activities link directly to research activities where SMN holds a leading position, nationally or internationally.
Selected laboratories must be upgraded, and methodological skills must be improved to give SMN the required minimum competence for successful development of prioritized programs at SMN that rely strongly on surface properties. This calls for some heavy equipment, for dedicated scientific staff, for technical assistance to ensure optimum running and finally, a decent running cost budget. In order to develop sufficient competence as well as links to relevant research projects, personnel (Phds, post docs, researchers, technicians) should be allocated to both surface science activities as such, as well to research projects that links surface science and prioritized research programs on materials science and nanotechnology.
The concept of mesoscopic physics has become popular about 15 years ago when it was clearly understood that novel electronic devices cannot be fully analyzed on the basic of traditional macroscopic physics. At that time the technology has become able to fabricate the devices of the sizes comparable to intrinsic scales described by quantum, rather then by classical mechanics. On the other hand, there are many specific features of small devices which cannot be described by a microscopic theory similar to atomic physics. Thus, mesoscopic physics is the research area specifically relevant to modern and future devices of submicron and nanometer scales. In addition, concepts of mesoscopic physics are crucially important for understanding electromechanical and magnetic properties if various nanomaterials, including granular systems and nanocomposites. At present time it is commonly understood that mesoscopic physics is a heart of nanoscience and nanotechnology.
The research group at University of Oslo possesses a profound expertise in physics of various micro- and nanodevices. During last years it contributed to several areas of mesoscopic physics including semiconductor materials and heterostructures, hybrid structures including superconductors, nanomechanical systems, etc. In addition, the group addressed several problems of mesoscopic physics studying properties of vortex matter in superconducting films. The typical scales of the vortex structure in such materials are actually in micron and submicron, rather than in nano-region. However, the intrinsic scales of the system lead to typically mesoscopic behavior, which was studied using unique technique of magneto-optical imaging.
Nearest plans of the research group are focused on the following directions:
· Stationary and non-stationary electron transport through granular materials, including self-assembled arrays of quantum dots promising for future optoelectronics.
Self-assembled arrays of Si-in-Ge quantum dots having a shape of pyramids of nanometer size are promising candidates for semiconductor lasers. Our foreign collaborators have performed systematic studies of high-frequency conductance through such arrays by measurement of attenuation and velocity of surface acoustic waves propagating in the vicinity of the sample. Our aim is to develop theoretical description allowing quantitative understanding of experimental results and optimizing the system performance.
· Electron transport through hybrid devices, in particular, those having superconductor and semiconductor parts. Such devices are key building blocks for superconductor-based electronics.
Interfaces between different materials are crucially important for nanotechnology since interface properties determine behavior of nanodevices. Our group is deeply involved in electron transport through interfaces. The ongoing project aims at theory of transport through an interface between a superconductor and a hopping insulator. Such an interface is present, in particular, in many modern devices for quantum computation. We have found a novel mechanism of charge transfer by coherent tunneling of electron pairs facilitating converting Cooper pairs in the superconductor to a pair of localized states in the hopping insulator. This mechanism can be responsible for a specific contact magnetoresitance. More theoretical and experimental efforts are needed for quantitative understanding.
· Quantum coherent devices serving as building blocks for future quantum computers. In particular, development of the theory of environment-induced decoherence.
The group extensively works on devices for realization of quantum algorithms. Such devices are based on different principles. Most of solid-state devices involve superconductors and Josephson junctions in combination with Coulomb-blockaded devices for single-electron logics. Recently, in collaboration with groups from USA, we have developed theoretical model describing decoherence in such devices due to dynamic structural defects. These models turned out to be very useful for interpretation latest experimental findings by several top-level groups. In particular, we will develop a theory for the devices for so-called quantum-gate operations. We will also address high-frequency spectral properties of the devices for quantum computations.
· Specific features of semiconductor devices fabricated according to 150 and 90 nm design rules, finding the ways for optimizing their performance. Such devices form nearest future of electronics.
We have found that in such devices there exist specific currents induced by electron tunneling from the gate electrode to the conducting channel. These currents put limits to performance of nanodevices, it is very important to understand their nature and decrease them. We have developed a theoretical model explaining main features observed by our collaborators. However, more experimental and theoretical work should be done. In particular, we plan careful investigation of noises in nanodevices.
· Experimental and theoretical studies of superconducting and magnetic materials focusing on mesoscopic phenomena and using profound expertise and unique equipment for magneto-optical imaging.
There are several project in our group aimed at studies of mesoscopic phenomena in superconductors and magnetic materials. The main motivation here is two-fold. Firstly, physical phenomena are determined rather by the ratio between the spatial scale characterizing distributions of relevant quantities to some intrinsic scales rather than by the length in nanometers. In this connection, vortex matter in superconductors is an excellent playground for mesoscopic physics.
Another important direction is using new equipment for scanning Hall probe spectroscopy to achieve mechanical manipulation small magnetic particles – so-called magnetic tweezers. Being developed, such possibility would lead to many important applications. Though the feasibility of the concept of magnetic tweezers has already been demonstrated, several issues, both in experiment and theory, remain open. The aim of this project is to clarify the situation and achieve the understanding of magneto-mechanics of small particles at a quantitative level. The project will be strongly facilitated by existing in the group expertise in nano-electro-mechanics.
· New equipment for thermo-optical imaging and for scanning Hall microscopy allows formulating new projects based on close collaboration between experiment and theory, such as studies of nano-patterned superconductors, manipulation small magnetic particles (magnetic tweezers), thermo-optical imaging of photovoltaic elements, allowing to optimize their performance, etc.
In particular, we are able to suggest an alternative method for monitoring functional properties of the latter devices. The thermo-imaging (TI) technique developed in our laboratory has higher temperature and spatial resolution compared to the conventional means of expertise (IR for example). High competitiveness of our method is provided by its relatively low costs at about the same operational complexity. Also it can be implemented for broad industrial use in a short perspective.
The field of nanosensors and –devices is extremely wide and challenging; it involves materials like semiconductors, superconductors and functional oxides in combination with device processing. The areas of application include ICT, energy and petroleum technology, medicine and pharmaceuticals. On the basis of scientific challenge, competence and infrastructure at SMN and collaborators, and the strategic relevance for Norway, the following specific areas have been identified as core ones for SMN.
- Optical and magnetic nano-devices
Currently, there is a considerable scientific interest for silicon-based structures containing individual crystallites with size in the nanometer (nm) range. Examples of such structures are crystallites of Si/Ge imbedded in insulating oxides (e.g., SiO2) and porous silicon with pors in the nm range. A main reason for this interest is the observation of efficient luminescence from such structures and the prospect of making silicon-based lasers.
Another hot topic is the use of thin film (~100 nm range) semiconducting oxides to accomplish light emitting devices operating in the blue/ultraviolet wave length range. A prime example of such an oxide is ZnO, with a direct bandgap of ~3.4 eV (at room temperature) and an excitonic binding energy of ~60 meV, but also other candidate oxides should be explored. Examples of major challenges are (a) synthesis of oxide films of sufficient device quality, (b) preparation of efficient p-n junctions for charge carrier injection and recombination, and (c) growth of quantum wires and quantum well oxide structures and how they can be addressed electrically and optically. Last but not least, semiconducting oxides doped with suitable metallic/magnetic elements may be very exciting candidates for spinntronic nanodevices.
- Nano-Electro-Mechanical-Systems (NEMS)
NEMS is a natural extension of MEMS (Micro-Electro-Mechanical-Systems) where there exists a strong infrastructure in the Oslo region on academic as well as on institutional and industrial levels. As a specific facility could be mentioned the new Micro- and Nanotechnology laboratory (MiNa-lab) in Gaustabekkdalen, a joint venture between SINTEF and UiO. MEMS is made possible by the phenomenal advances in the manufacture of mainstream silicon devices. Also for NEMS, silicon technology is anticipated to constitute the main basis but presumably to a less extent than for MEMS. On the nm-scale new physical phenomena occur and combination of silicon with other materials like ‘new’ semiconductors, functional oxides, etc., which may exhibit superior mechanical properties on this length scale, is a very demanding area of research with great potential for NEMS. Anticipated areas of application are numerous like, for example, microfluidics in biochemistry and biomedicine, RF wireless components (resonators, varactors, switches and filters), optical interferometry and medical pressure sensors.
- Molecular Electronics
This is a scientific field with a huge potential and perhaps, one of the most exciting ideas in molecular electronics is to use DNA as a building block of electronic devices. Indeed, due to its role in biological systems, DNA offers unprecedented possibilities in building up self-organized micro- and nano-systems. It has been long discussed, however, whether DNA can be used for a long-range electron transport. Recently it has been realized that the transport properties can strongly depend on the set of the nucleic acids. However, the introduction of DNA in an electronic circuit faces the issues of (a) controllable deposition, (b) metal-DNA contact quality, and (c) the sequence and type of the nucleic acids. For a successful progress in this field with respect to manipulation and design of DNA for electronic devices, a close interaction between research groups in molecular bioscience, materials science and device preparation is required and will be established.
Another key area in molecular electronics is carbon nanotube (CNT) field effect transistors (FET), which recently have been demonstrated in simple logic circuits. Despite such progress there are a large number of scientific challenges to be met before CNT electronics can replace/complement the conventional semiconductor one. Some specific examples are (a) controllable deposition of CNT on electronic structures, (b) quality of electrical contacts between metal and CNT, and (c) the influence of structural defects in CNT on the charge transport properties. Collaboration in this area is foreseen with IFE (in addition to international partners).
- Chemical sensors
Gas sensing devices that can be operated under harsh conditions regarding temperature and ambient (environment) are of utmost strategic importance and scientifically very challenging. One promising approach is to use thin insulating oxides layers (£100 nm) deposited on inert wide energy bandgap (³3 eV) semiconductors in order to form a field-effect device where variations in the so-called flat band voltage are employed for selective gas detection. In particular, ‘alternative’ oxide films (with respect to SiO2) with high dielectric constants, e.g., Al2O3, ZrO2 and HfO2, are considered to be of main interest. A second, and perhaps more futuristic, concept is the use of quantum dots (QD’s) on surfaces; as the local electron structure depends on atomic species and coordination (shape and size of QD’s) it is in principle possible to design a QD to initiate a specific/selective reaction when a gas phase molecule is approaching the QD. As a result, charge transfer may occur between the QD and the molecule, which can be monitored by nanoprobe techniques like scanning tunneling microscopy. Examples of candidate material systems that are currently attracting a lot of interest is QD’s of gold dispersed on metal oxide surfaces like TiO2 and MgO.
In the Oslo area clear possibilities for collaboration within nanotechnology exist with the research institutes FFI, IFE and SINTEF, with the hospitals and with industry. For SMN the possibilities for joint projects and sharing of costly infrastructure with the research institutes are described below on the basis of discussion meetings and suggestions from the external research partner.
Background and research interests. FFI has for many years been involved with experimental solid state physics, microtechnology and electro-optics in the Epitek laboratory. The Epitek lab has two of the three molecular beam epitaxy (MBE) machines in Norway, a large cleanroom, photolithography, and a lot of characterization equipment (see list below). The two MBE machines were originally used to grow two different compound semiconductors – AlGaInAs og CdHgTe. The AlGaInAs machine was originally run by Televerkets forskningsinstitutt. Today both machines belong to FFI, but only one is in regular use. FFI has focused on the semiconductor CdHgTe, which is used to make detectors for infrared (IR) radiation (the band gap in the HgTe/CdTe system can be varied from 0 to 1.5 eV, which covers the entire IR region). This material system is used to produce 1- and 2-dimensional (2D) photodiode arrays within several IR wavelength bands. In addition to MBE growth of CdHgTe and IR detector fabrication, FFI has done a lot of materials science studies on the CdHgTe material system, including growth, processing and characterization of different quantum structures and their basic structural and electronic properties. Quantum wells/superlattices have been grown in both the CdHgTe and the AlGaInAs material systems, energy levels measured by the magneto-optic effect, and a GaAs/InGaAs quantum well IR detector has been demonstrated.
In this respect FFI has a large (and rather unique in Norway) expertise in crystal growth, electro-optics and work with various sensors. Norway’s largest research activity in electro-optics is at FFI, and it has resulted in several new companies. The institute also participates significantly in international research collaborations.
FFI has already started to extend parts of this type of work into the nanotechnology area. The goals will be both ‘technology watch’ and to study processing and characterization of new types of sensors or radiation sources. The main goals are to make semiconductor nanostructures, mainly in CdHgTe, and to demonstrate physical effects of nanostructuring that can constitute the basis for sensors and electro-optic components. Such components could be LEDs, lasers, detectors in different spectral bands, single photon sources etc. In these projects FFI consider it important to collaborate with other scientists in Norway and abroad..
FFI is interested in both quantum wells, nanowires and quantum dots. The semiconductor CdHgTe has a direct bandgap that can be varied over the entire infrared range (0-1.5 eV). The material also has some special properties such as small electron mass, high electron mobility and large g-factor. Quantum effects are expected in larger dimensions and at higher temperature than in other material systems. The reduced dimensionality of nanostructures reduces Auger generation/recombination, which is usually a problem in bulk narrow-gap semiconductors. Nanostructures in CdHgTe may therefore be especially well suited for electro-optic components.
Collaboration - equipment, research projects and research training. A lowest level collaboration would be access for SMN and FFI scientists/students to use equipment at the other institution. This is already taking place to some extent, e.g. access for FFI to the force microscope (AFM) at SMN and vice versa access for SMN to Hall and high resolution x-ray diffraction measurements at FFI. Ideally, the interested scientist should be taught to run the equipment in question without any later operator assistance. However, very specialized equipment would require operator assistance. In some cases, access might require a security clearance. The equipment at FFI of possible interest to SMN includes MBE growth systems and advanced characterization (XPS/Auger, FTIR, High resolution x-ray diffraction, SEM with electron beam induced current, Hall effect, Probing station, Photoluminescence setup for quantum wells). FFI holds processing capabilities including photolithography, wet etching, ion milling/sputter deposition, bump and wedge bonding machines, annealing ovens and thermal evaporation deposition.
SMN has several laboratories of interest for SMN, amongst others TEM and XPS. SMN and FFI will explore the possibility of joint funding of core personnel in order to provide FFI access to relevant services. This will be seen in a broader connection with similar needs at other research institutes in the Oslo area.
FFI and UiO (UNIK) are already sharing students, until now at a low level. It should though be mentioned that several master students or master candidates have made their compulsory military service in research laboratories at SMN, which indirectly provide links between FFI and SMN. More extensive collaboration involving students are foreseen on projects of joint interest for FFI and SMN.
Both SMN and FFI are interested in quantum wells, nanowires, nanotubes and quantum dots. Although the materials of interest are different, there should still be plenty of room for close collaboration. One may collaborate on growth of certain materials (e.g. tellurides, oxides), inclusive adding layers of one type of material on top of another (MBE, ALCVD, MOCVD). The skills in growth of nanoparticles at SMN may together with expertise in sensor systems at FFI open up for joint projects on nanostructured sensors. Likewise, collaboration on growth and characterization of quantum dots may provide an experimental activity above critical size. Furthermore, the expertise at SMN on electronic structure calculations could help providing more insight into properties of e.g. CdHgTe semiconductors. Expertise gained and measurements techniques developed for certain nanostructures may be shared between the institutions. Development of manipulation schemes and contacting processes for nanostructures could be useful regardless of material. Joint proposals to the Research council of Norway or to EUs framework programme may provide good means for funding a few prioritized joint projects. SMN and FFI will invite the other institution to join EU proposals whenever this is reasonable for scientific reasons.
FFI and SMN, along with other UiO partners, may together have adequate skills for exploring e.g. nanowires as detectors for chemical and biological molecules. As the nanowires are very small (large surface-to-volume ratio) the sensitivity of such a sensor can be very large, with the possibility of detecting a small number of molecules. The challenges involved are very large, nevertheless, such a project would link to prioritized activities at SMN, e.g. within growth of nanoparticles with morphology control and within nano-devices/-sensors.
SINTEF has several activities of relevance for SMN in the area of nanotechnology. Two areas are of particular interest since UiO (SMN) and SINTEF has established so called Gemini centres; MiNa-Lab (Micro- and Nanotechnology laboratory) and CATMAT (catalytic materials and adsorbents). These are given focus below. In addition, the materials and chemistry division at SINTEF has extensive activities on nanoparticles and their use in various technologies. SMN has extensive collaboration with SINTEF on functional materials and microtechnology. Most projects involve master students, PhD-students or post docs. The SINTEF staff holds two adjunct positions at UiO, thus contributing significantly to teaching and education. Several students are supervised jointly by SMN/UiO and SINTEF.
MiNaLab. The running and future research activities in MiNaLab are of common interest for both SINTEF and UoO. SINTEF intends to put a strong priority in these areas, in which more detailed priorities will be defined through common strategic process in spring 2005. The priorities will be followed by common or coordinated research proposals/applications.
The following areas are from SINTEFs point of view the most important:
Within this area, two main areas are in of focus:
- Process development in which processes for nanostructuring (through nanolithography, by formation of porous silicon or by oxidation and etching) will be developed and materials/components will be characterized. Independently, or combined with bulk or surface micromachining, these processes will form the basis for developing new sensors and actuators.
- Device development, primarily aimed at developing devices that could be used to demonstrate possible applications of new process technology or devices used for characterization of nanomaterials (i.e. development of different templates).
- SINTEF and UiO/UNIK will together with Stanford University further explore ongoing collaboration within optical MEMS and NEMS. This collaboration includes diffractive optics and photonic crystals for spectroscopic applications.
Functional materials deposited by MOCVD, ALCVD or other techniques (at SMN) hold promising applications in NEMS and MEMS. Of special interest are ferroelectric materials with possible use both in sensors and actuators. In principle, all materials that could be used for sensor purposes are of interest. The research at SMN covers a large range of relevant materials (e.g. multiferroics, CMR, ionic conductors; nanorods and nanotubes). There are, however, some properties that are vital for such applications, that is:
- Techniques should be established to deposit these materials on silicon wafers which often require development of intermediate stress relief layers.
- The functional properties of the materials must be characterized. The ability to reproduce and control the material properties will be important for exploitation of the results. This will frequently imply control of the microstructure.
- Long term stability, specificity, selectivity and the hysteresis of the materials should be characterized.
SINTEF and SMN/UiO intend to develop a reliable technology for fabrication of advanced 3D silicon radiation detectors for medical, industrial and scientific applications. In order to achieve this objective, there are challenges from process development to understanding of the detectors, where UiO will mainly focus on the underlying physics of fabrication and operation of the devices while SINTEF will focus on the device design and process development. The scientific research efforts will be on process development, materials characterization, electronic properties of the structures and their sensitivity to controlled environmental stimulus, defects and carrier distributions in the 3-D detectors, surface passivation and localized electronic interface states.
Catalytic materials and adsorbents; CATMAT
In the CATMAT activities SMN will focus more on underlying chemistry, materials science and physics for catalysis, adsorbents and functional surfaces, whereas SINTEF will have more focus on applications. However, there will be fields/niches where SMN will also focus on applications as well as fields where SINTEF holds a leading role on fundamental science. The Gemini-centre is a token that indicates that SMN and SINTEF together hold a high scientific level within catalytic materials and adsorbents; and a potential that is of industrial interest.
The strategy for science and collaboration within CATMAT builds on the expertise of SMN (see section 3.1.) and SINTEF. Four areas are in main focus (briefly exemplified):
- microporous and mesoporous materials with open porosity (pore diameters around 1 – 15 nm). Such typically acidic catalysts are of interest for several industrial processes, many connected to oil and gas conversion. The high international standing of SINTEF and SMN, owing to the first synthesis of several materials with new microporous topologies and their work along the line from basic research to development of new catalysts that now are about to be implemented on large scale in novel routes for chemical conversion (methanol to olefins), makes CATMAT attractive as partner. A main challenge is ability to synthesize (design) nm-sized pore structures with optimum topology and acidity of active sites on the basis of insight in reaction mechanisms.
- metalorganic framework structures (MOFs) with open porosity on the nm-scale is a recent field with strong collaboration between SMN and SINTEF; on adsorbents (hydrogen, carbon dioxide); on heterogenization of otherwise homogeneous catalysts. The field is considered to have significant potential for applications. A major challenge is to provide materials with sufficient stability and “capacity” to a competitive cost.
- nanoparticles as catalysts, with focus on novel routes for depositing or developing nanocrystals on surfaces and supports. E.g. SINTEF and SMN have a 10 y record with collaboration on layered materials, in particular hydrotalcite related materials, which are explored as supports for petrochemical reactions. One focus point is the use of knowledge gained from in situ studies of catalyst formation, of growth of metallic catalytic sites during activation, of deactivation, etc for catalyst improvement.
- fast throughput methods (combinatorial methods) is a field where SINTEF holds world leading competence. Such methods are already integrated into collaborative projects with SMN; for studies of phase formation (nanoporous materials) from solvothermal synthesis exploring a complex parameter space; for improvement of crystallinity of nanoporous materials; and for property testing. Focus will be further integration of fast throughput methods into the three materials fields mentioned above in addition to methodological developments at SINTEF.
Several groups at IFE are already involved in nanotechnology research. IFE has long traditions for close collaboration with UiO within chemistry, physics and materials science. Extension of these into nanotechnology is thus quite natural. IFE and UiO have recently signed a new collaboration agreement, pointing inter alia at materials and components for energy technology as a joint focus area. IFE and UiO have furthermore well developed collaboration involving master and PhD-students, joint post docs and adjunct positions connected with teaching or research.
Nanoparticle fluids and nanomagnetism:
The Physics department at IFE has had a research activity on the properties of ferrofluids and colloids going on since 1983. Ferrofluids are colloidal suspensions of magnetic nanoparticles in a carrier fluid. The magnetic particles are of typical size 5-50 nm. Ferrofluids were one of the first examples of nanotechnology products which were available, and have now a wide range of applications, from vibration dampers in truck seats to air tight, frictionless seals in rotating shaft, for example in hard-disk drives. The research at IFE has in particular focussed on the properties of mixtures of ferrofluids with micro- and nanoparticles (viruses, colloidal microspheres, clay particles) and the ability to make regular lattices with nm precision control of particle separations, with possible applications in photonic crystals. The structure of various ferrofluids has, in collaboration with several groups abroad, been investigated by neutron scattering techniques in the JEEP-II reactor. IFE has also one patent on the use of ferrofluids. This topic connects naturally to growth of nanoparticles with morphology control at SMN, several of the candidate oxides being ferro- or ferromagnetic materials at room temperature. SMN possesses furthermore advanced tools (MPMS, PPMS) for characterization of magnetic particles.
Nanocarbon and nanoparticle fluids:
IFE, in collaboration with the T-TEC company, is running a pilot production facility for carbon nanotubes. The purpose of this project is to be able to produce large quantities of carbon nanotubes at a relatively cheap price, which would facilitate the use of carbon nanotubes in composite materials. Dry nanocarbon particles as well as mixtures of nanocarbon in liquids are being studied using neutron and x-ray scattering and scanning electron microscopy. IFE has also a patent on the use of carbon nanocones as a possible hydrogen storage material, and there is now both theoretical and experimental work going on in order to verify this.
Hydrogen storage and nanostructured hydrides:
There is a large activity on hydrogen storage in metal and complex hydrides at IFE. This activity is strongly dependent on the availability of neutrons from the JEEP-II reactor at IFE. Nanoscience has the potential to provide revolutionary new capabilities that will have a profound impact on hydrogen storage. Improvements in today’s metal and complex hydrides can be achieved by careful design of nanoscale architectures that include dopants and tailored voids to improve the weight percentages of stored hydrogen and provide control of the kinetics and thermodynamics of hydrogen uptake and release. Fundamental research on nanostructured hydrides may also provide insight into the atomic and molecular processes responsible for the interaction of hydrogen with the hydrides, kinetics of hydrogen absorption/desorption, mechanisms associated with degradation and effect of additives. SMN has long traditions for collaborating with IFE on hydrogen storage materials. SINTEF has more recently entered into the collaboration with respect to complex hydrides. At SMN special attention is given to theory and modelling of properties and stability of candidate materials. Recent projects focus at SMN focus on how materials properties are affected by turning to nanoscale dimensions. The role of nanosized catalysts for achieving reversible hydrogenation of complex hydrides is another topic of joint interest.
Nanoporous gels, polymers, and complex fluids:
The small-angle neutron scattering instrument at IFE is well suited for studying the structural properties of polymer solutions and polymer gels, since these contain typical clusters or pores on the nm-scale. There is a broad ongoing national collaboration in the Collaborative Research Group COMPLEX.on the properties of nanoparticle silicate suspensions (clays) and similar nanoporous materials. Extensive collaboration exists furthermore with UiO on polymer chemistry. At SMN (in collaboration with SINTEF) the activities on delamination of layered materials giving well defined colloidal suspensions benefit from collaboration with IFE on small angle scattering. Such suspensions of e.g. nanosheet oxides may have potential as model materials within the COMPLEX project. Several other research topics at SMN on nanoparticles/colloidal particles would benefit from stronger interaction with competence at IFE; e.g. studies solification and gelification subsequent to hydrolysis of metal-organic solutions (i.e. sol-gel route for spin-coating) and initial stages of hydrothermal synthesis of microporous materials.
A few other research topics at IFE of some relevance for SMN and UiO are briefly mentioned. One such is Corrosion inhibitors and surface modification. The Materials and Corrosion Technology Department at IFE are interested in nanostructured coatings made from nanoparticles for mitigation of CO2 corrosion of carbon steel. The major potential benefits of such coatings may be the combination of a barrier coating and chemical inhibition provided by chemicals incorporated in the nanoparticles or at their surface. The small size of the building blocks is likely to be essential for the performance. E.g. the mechanical properties with respect to cracking of a coating are expected to improve. A second relevant topic is Nanoparticles in chromatography, chemical separation and tracer technology. IFE is here interested in production of isotopic pure materials through diffusional chromatography. This may involve the use of monodisperse particles (<10 micrometers) in continuous separation and testing. Of particular interest is isotopically pure silicon. Nanoparticles may also be of great interest for radioactive scale inhibition where deployment and dissolution mechanisms are important, and as tracers (and radiotracers). The ability to modify surface properties of nanoparticles is important in this connection.
Nanotechnology is foreseen to have a large impact on medical research, pharmacy (drug delivery), biomaterials, and the interface between biotechnology and materials technology more generally. At UiO, these possibilities are addressed by the steering groups of the EMBIO and FUNMAT prioritized efforts. The Oslo area, i.e. UiO and the neighbouring hospitals (Rikshospitalet, Radiumhospitalet, Ullevål and Aker universitets-sykehus), holds a broad, very competent, and rather unique knowledge in Norway that has a major potential for significant synergies with respect to crossdisciplinary research at an interfaces where nanotechnology plays a large role. SMN has initiated, and will for the time being host network meetings for nanotechnology connected with soft materials and life sciences. A few selected issues for further discussion and planning are described below.
With the aging population there will follow a major increase in the demand for replacement treatments and advanced diagnostic tools. The biological and medical sciences search for cost effective, improved analytical systems and sensors for studies of molecular interactions in biological systems, structure of biological molecules and sequence analysis of nucleic acids and proteins. Biological and cellular processes are inherently nanoscale phenomena, thus nanotechnology is important for understanding and manipulation of these processes.
Moreover, new knowledge of molecular mechanisms and chemical interactions between living cells and surfaces has opened for a direct approach for the development of bioactive materials for use in medical devices and biosensors. Through nano- and micro- structural surface modifications on implants one is able to improve the performance of metal replacements in the skeleton dramatically. Such smart surface materials with improved biocompatibility are the first step toward true biomimicking materials.
Of special interest to materials science is the development of new biomaterials for use in dentistry and medicine. The ultimate aim for biomaterial science is to develop materials that structurally, chemically and mechanically mimic the natural tissue they are to replace or assists. Since it is the surface of such materials that directly interact with the surrounding tissues and cells, special emphasis has been given to the (nano)structure and (bio-)chemistry of the biomaterial surfaces. Through development of molecular imprinting and micropatterning of surfaces it is expected that materials will be developed that not only are accepted by the recipient tissues, but also actually integrates and functions even at the molecular level, as a normal part of the human body. To develop such biomimicking materials one will have to investigate the interaction between cells and the material surfaces, and develop strategies that take advantage of cellular structures for attachment, spreading and signal transduction.
Intelligent design of micro- and nanocapsules for drug delivery is a field where crossdisciplinary research between groups in chemistry and pharmacy may lead to new concepts, materials and delivery systems. Current pharmaceuticals are rarely disease specific, frequently they are unstable in biological milieu and undergo rapid clearance and metabolism. Nanoscale drug carriers may open up for targeted and sustained drug delivery, advantages being inter alia solubility enhancers, protection from degradation in biological fluids, sustained/controlled release systems, cellular uptake and altered pharmacokinetics. Polymeric-drug conjugates, liposomes, polymeric micelles and dendrimers are all attractive for biological and drug delivery applications. The competence in the Oslo area should provide good possibilities for focused collaborative projects in this field. A niche that appears very attractive is to focus on nano-sized delivery systems that can be combined with PET imaging methods at Rikshospitalet.
Possible environmental and health aspects connected with nanoparticles have already become an issue, partly because of asbestos like appearance of nanorods, carbon tubes, etc. and the small size of nanoparticles that may allow transport through biological membranes. Such issues can be address through crossdisciplinary projects, involving chemistry, toxicology, medicine and environmental sciences.
Nanoparticles are a part of our environment since a major share of the number of particles in air pollution (aerosols) is indeed of nanometer-size, although representing a minor fraction with respect to weight. Certain environmental issues may hence benefit from the mentioned focus on nanoparticles. The tools required in nanotechnology for characterizing nanosized objects and surfaces, are indeed tools required to chemically and microstructurally characterize nanoparticles in the environment. This could open up for new initiatives on sharing advanced characterization equipment.
Functional nanostructures based on biological molecules such as peptides, proteins and DNA have already been developed. In particular, the inherent properties of DNA molecules offer an attractive approach to the building of nanodevices, by providing a structurally well-defined ‘smart glue’ that combines both sticky-end cohesion and affinity. Thus, DNA can be used to control the geometry and interaction with other molecules such as proteins to produce arrays and lattices making molecular networks
International collaboration is specifically important for emerging research areas, such as nanotechnology. It allows accumulating expertise of leading research groups throughout the world and creating knowledge. A natural step is making use of international collaboration existing at participating research groups. All the SMN partners can demonstrate impressive lists of foreign partners and joint projects. The main part of the SMN strategy is preserving existing collaborations. In addition, new topical agreements for collaboration are either already initiated, or will be initiated in the nearest future. These agreements involve SMN as a whole entity. Examples of such collaborations are the agreements between SMN and
- Argonne National Laboratory (USA) and
- Center for National Research, Institute of Microelectronics and Microsystems (Italy).
These collaboration projects include exchange visits, both by young and mature researchers, as well as topical workshops. Examples of such workshops are Bi-lateral Meeting organized by Italian embassy in Oslo (October, 2004) and annual extended (2 months) workshops on Superconductivity and Magnetism at Nanoscale at Argonne National Laboratory. In addition to the obvious potential for extensive scientific collaboration, such links are important for strengthening the education. A recent example is the adjunct professorship sponsored by SMN for attracting leading knowledge, prof. Lars Samuelson, from the XXX laboratory in Lund.
In addition to strengthen existing collaborations, e.g. through existing agreements, SMN will seek to consolidate and strengthen collaboration with top level nanotechnology laboratories worldwide.
Traditional characterization tools typically average over the entire sample, and traditional instruments are designed for macroscopic-sized samples for which the signal is relatively strong. To understand and control nanomaterials, it will be invaluable to examine structures and properties on the nanoscale and to make measurements on individual nanostructures. A further challenge is parallel nanocharacterization of more than one property at the same time.
SMN holds a broad range of novel and state-of-the-art synthesis and fabrication capabilities in support of its advanced facilities for the measurement of structural, physical and chemical properties on the nanoscale. At SMN experimental activities is already efficiently linked to very well established theory of nanometer-sized systems. It is important that theoretical efforts are concentrated both on fundamental problems and concrete materials and devices. Computer simulations provide an important link between theory and experiment, which is particularly crucial for the case of nanoscale structures. While experiments provide the critical test cases against which simulation methodologies can be validated, simulations can provide complementary insights not readily obtainable from experiments alone. The present combination of expertise in these areas at SMN is unique in Norway.
The MiNa-lab (and the Gemini-centre collaboration with SINTEF) provides excellent opportunities with respect to clean room facilities and fabrication of microtechnology components. Yet, several challenges must be addressed. The new laboratory is in strong need for modern equipment on a time scale of 3 to 5 years, primarily upgrading old processing equipment from early microtechnology activities. The advanced laboratory needs strongly basic funding for covering normal infrastructure costs and technical support. The clean room has limited capacity to take up all new planned activities in nanotechnology and the space for students and dry labs has already become a bottle neck.
SMN has strong qualities, competence and equipment for synthesis and characterization of nanostructured materials. These existing strengths and possibilities could be communicated to partners and the public in terms
- laboratory for synthesis of nanostructured materials
- laboratory for complex physical characterization of nanostructured materials
- laboratory for theory and electronic structure of nanostructured materials
New investments in these laboratories should connect directly to the five prioritized research programmes at SMN within nanotechnology. The possibility of having access to equipment at collaborating regional institute partners should as far as possible be integrated into research activities in order to avoid spending resources for investments in overlapping equipment.
SYNTHESIS CHARACTERIZATION THEORY - MODELING FABRICATION - APPLICATION Nanotech TOOLS
THEORY - MODELING
FABRICATION - APPLICATION
The needs for upgrading and new scientific equipment should be seen in close connection with activities within the five prioritized nanotechnology programs at SMN. Such needs for advanced instrumentation do exist for e.g. nanomaterials synthesis and fabrication, nano-texturing, mechanistic and in-situ studies of nanomaterials at real conditions, surface studies, physical characterization, device and sensor testing. The real extent of SMN activities in nanotechnology will thus depend on the funding level and the funding profile. Though absolutely required short term investments in an initial phase are estimated as modest (some 2 – 4 MNOK), the medium term needs for instrumentation for the five prioritized areas easily sum up to several tens of millions Norwegian kroner.
Experimental activities in nanotechnology at the cutting edge tend to be very expensive and have typically some interdisciplinary character. Certain laboratories at SMN should be identified for achieving particular funding for covering of infrastructure and running costs. These laboratories must have key functions within nanotechnology at SMN. There is clearly a special need for dedicated funding for covering infrastructure costs at the MiNa-laboratory, crudely estimated to 2 MNOK/y. Other candidate laboratories for special funding are inter alia the TEM, SIMS, XPS, XRD, magnetic and electric characterization, growth and in-situ laboratories. The funding of key personnel, that is dedicated technical staff and scientific specialists within prioritized niches of nanotechnology, must have a long term perspective. Otherwise the effort of building up competence to an international high level will soon be in vain.
The SMN vision is that the advanced characterization tools will act as a national strong point in nanotechnology and as a joint resource for many activities in the Oslo area.
Arb.gruppen skal lage en konkret forskningsstrategi for nanoteknologi ved SMN, med utgangspunkt i utredningen som er foretatt i regi av FUNMAT@UiO i 2003-04. Overordnede aspekter i SMNs strategiplan og SMNs kriterier for prioritering av satsingsfelt skal vektlegges.
Arbeidsgruppen skal legge opp til en forskningsstrategi som som skal være konkret når det gjelder forskning relatert til
- anbefalingene fra den internasjonale ekspertgruppen til FUNMAT@UiO
- strategisk samarbeid med IFE, FFI og SINTEF, spesielt innen de områder der samarbeidsavtaler er inngått
- fagfelt ved UiO som SMN på kort eller lang sikt bør etablere aktivt samarbeid med (myke materialer, biomaterialer, medisinsk teknologi)
Strategidokumentet skal være egnet for
- beslutninger når det gjelder oppstart av konkrete samarbeidsprosjekter innen nanoteknologi ved SMN og med partnere utenfor SMN
- beslutninger når det gjelder samarbeid rundt eksisterende tungt vitenskapelig utstyr når det gjelder de prioriterte, regionale samarbeidspartnerne
- beslutninger vedrørende behov for oppgradering av eksisterende laboratorier for å dekke tiltenkt rolle innen nanoteknologi
- videreføring av strategiprosess frem mot en neste fase for oppbygging av nanoteknologi ved UiO med et evt dedikert senter
- å formidle til forskningsråd og departementer hvilke kvaliteter som SMN besitter innen nanoteknologi, hvilke samarbeidskonstellasjoner som bør utvikles, og på det grunnlag danne basis for dialog mellom SMN, UiO og finansieringskilder om hvorledes SMN kan fylle tiltenkt rolle som strategisk virkemiddel for nanoteknologi ved UiO
 “… Coated nanoparticles dispersed in a carrier liquid, known as ferrofluids, are an early success story in the commercialization of nanotechnology. …”, J.D Linton and S.T. Walsh, Commentary in Nature Materials, May 2003.
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