Why are nano-structured materials different from macro-structured ones ? Which nano-structured materials are currently studied by researchers ? Which classes of applications will be influenced by them?

Nano-structures are materials with size features on the order of several nanometers. These could be: quasi-2 dimensional (e.g. quantum wells), quasi-1 dimensional (e.g. nanowires), quasi-0 dimensional (e.g. quantum dots), porous materials with nano-sized pores (e.g. aerogels).

Their small size endows them with interesting optical, electric, chemical, mechanical, thermal, and magnetic properties. They are flexible as their properties depend strongly on their size but their unusual behavior is still difficult to control and exploit.

Is it possible to create and control structures that consist of several thousands of atoms only? Are nano-fabrication processes suitable for mass production ?

Nano-fabrication techniques can be bottom-up (e.g. molecular self assembly) or top-down (e.g. electron beam lithography). Some of them are widely spread (e.g. chemical vapor deposition), some of them were only recently used for mass production (e.g. electrospinning) and others are still being improved by researchers (e.g. molecular self assembly).

The resolution can be as low as 5 nm, the actual values depending on the technique employed.

One of the factors that contributed decisively to the development of nanotechnology was the impressive improvement of microscopy techniques and the advent of scanning probe techniques.

These instruments are used not only for imaging of nano-scale objects but for measuring the interactions which occur at molecular level. Even manipulation of individual atoms is possible!

Some spectroscopy techniques are quite useful for real-time monitoring of nano-fabrication processes (e.g. ellipsometry) or for the structural analysis of nano-structures (e.g. infrared spectroscopy).

Characterization of large (bio-)molecules is possible by using nuclear magnetic resonance and mass spectrometry.

This section presents how nanotechnology is or can be applied in fields as: drug delivery, tissue engineering, medical imaging, photonics, electronics, automotive industry, textile industry, cosmetics, water purification, thermal insulations, and energy conversion, electrical-neural interfaces.