Nanoscale devices

In this final chapter, we will review the current frontier of the applications of CNTs. Nanoscale applications such as nanoscale devices and ultra-fine probe, as well as macroscale applications such as field emission, energy storage and... 

In this chapter we describe the basic principles involved in the controlled production and modification of two-dimensional protein crystals. These are synthesized in nature as the outermost cell surface layer (S-layer) of prokaryotic organisms and have been successfully applied as basic building blocks in a biomolecular construction kit. Most importantly, the constituent subunits of the S-layer lattices have the capability to recrystallize into iso-porous closed monolayers in suspension, at liquid-surface interfaces, on lipid films, on liposomes, and on solid supports (e.g., silicon wafers, metals, and polymers). The self-assembled monomolecular lattices have been utilized for the immobilization of functional biomolecules in an ordered fashion and for their controlled confinement in defined areas of nanometer dimension. Thus, S-layers fulfill key requirements for the development of new supramolecular materials and enable the design of a broad spectrum of nanoscale devices, as required in molecular nanotechnology, nanobiotechnology, and biomimetics [1-3]. 

Small gold clusters (<100 atoms) have become the subject of interest because of their use as building blocks of nanoscale devices and because of their quantum-size effects and novel properties such as photoluminescence, magnetism, and optical activity [427]. 

D. Zhou, A. Chu, A. Agazaryan, A. Istomin, and R. Greenberg, Towards an implantable micro pH electrode array for visual prostheses, in Nanoscale Devices, Materials, and Biological Systems Fundamentals and Applications (M. Cahay, ed.), pp. 563-576. Electrochemical Society (2004). 

Frederiksen T, Paulsson M, Brandbyge M, Jauho A-P (2007) Inelastic transport theory from first principles methodology and application to nanoscale devices. Phys Rev B 75(20) 205413-205422... 

Nakamura H, Yamashita K, Rocha AR, Sanvito S (2008) Efficient ab initio method for inelastic transport in nanoscale devices analysis of inelastic electron tunneling spectroscopy. Phys Rev B 78(23) 235418-235420... 

Of course, it is impracticable to synthesise nanoscale devices based solely on covalently-linked bridged systems and it is reassuring to learn that ET is also strongly mediated by H-bonded networks and by solvent molecules, thereby opening the way for the construction of photovoltaic supramolecu-lar assemblies. 

The motivations for the study of biomolecules immobilised on surfaces, briefly outlined above, also provide an explanation for the increased popularity of microscopy-based techniques. Indeed, while for single molecule and self-assembled layers the use of microscopy techniques is obvious, the commercial biodevices are increasingly micro- and even nanoscale devices. 

Alper, Joe. Self-Assembly Getting Molecules to Put Themselves Together to Make Nanoscale Devices. Available online. URL http // nano.cancer.gOv/news center/monthly feature 2005 jul.asp. Accessed May 28, 2009. This feature article, published in a newsletter for the National Cancer Institute, offers an accessible tutorial on self-assembly and supramolecular chemistry. 

Koratkar, N. (2003) Nanoscale devices for thermal, mechanical and chemical sensing. Proc. Inti. Conf. on Nano Science and Technology, Kolkata, India, Dec. 17-20, 2003, p. 55. 

Similar educational opportunities abound for carbon. The diamond and graphite allotropes of carbon have been mainstays of chemistry classes for generations of students and provide a contrast between a three-dimensional structure of great hardness and a two-dimensional structure with lubricant properties, respectively. We now have what can be regarded as zero- and onedimensional counterparts - buckyballs and carbon nanotubes, respectively - with their rich diversity of structural relatives and physicochemical properties (4). These materials are being employed in a variety of nanoscale devices because of their unusual chemical, mechanical and electrical properties. 

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