Track-etch membranes enabled nano-/microtechnology: A review

The art and science of fabricating structures with nano-/micrometric dimensions as well as precision is of the immense concern to any one investigating into nano-/microtechnology. The synergetic support of radiation and its potential in combining radiation effects with nano-/micromaterials has been recognized from the very early stages of nano-science research. In the myriad of applications and uses of nano-/microstructures, and nano particles in particular, from filtration, fabrication of biosensors, a chemical catalysis, magnetic structures, nano-electronics, MEMS, mechano-chemical conversion, quantum computing etc to name a few, radiation can play a significant role. One such potential application is track-etch membranes- a spin-off from the matter-radiation interaction. In the recent years, there has been a tremendous leap in the potential applications of metallic as well as non-metallic nano-/microstructures and materials. Nanotechnology has initiated a big hop and appears to be all set for bringing in revolution in the development and advancement of techniques involved in the synthesis and fabrication of sensors and devices. The conventional techniques for fabrication of very low dimensional wires - say quantum wires, include wet chemistry, electron beam lithography, focused ion beam techniques and atomic-beam lithography but for certain drawbacks and problems mentioned further. That has shown the ways for adopting newer alternative approaches which are relatively inexpensive, easier to handle and synergistically adorned with high efficacy. It is now well known that size of the devices and components dictate many unusual traits where quantum effects become more predominant. Quasi-one-dimensional nanostructures and materials like nanowires, fibres, tubules etc, having high aspect ratio would provide unusual and uncommon properties. Some properties like strength and hardness enhancement, dramatic changes in electrical conduction, field-ion-emission through tunneling phenomenon, optical, magnetic, and chemical and other important functional attributes etc are found to be enhanced when the size reduction comes into play. This review article addresses the art and science of specific technique-the Template Synthesis(TS) used as a route in the development of nano-/micromaterials and structures involving metals, non-metals, semiconductors, magnetic multilayered nanowires, conducting polymers, glasses, nanotubules, wires and whiskers etc. The recent past has witnessed keen interest being generated on the use of innovative technologies like TS in the production of nanomaterials' fabrication reported from various authors and from our lab. The strategy for embedding matter of interest within the etched pores or channels in the template is the material's placement through some suitable mechanism at the desired places viz., pores. (C) 2009 Elsevier Ltd. All rights reserved.