Nanophysics and nanotechnology applied to sensors, part 1

Miniaturization is a reliable recipe toward higher efficiency and lower cost of sensors and has fortunately led to the discovery of entirely new devices. Quantum mechanical effects tend to appear as the size of devices decrease. In the development of higher performing computer chips, a deleterious quantum effect, tunneling leakage through the gate insulator, was circumvented, by use of "high kappa oxides". In a very important case, a new sensor, the magnetic tunnel junction, is an entirely "nanophysical" device. The magnetic tunnel junction MTJ or "tunnel valve" sensor has greatly improved disk drive performance and has had a large economic impact. Nano sized components, such as the carbon nanotube, permit novel sensors and can sense polar molecules. Even optical detection of single virus particles is possible and was described.