ABSTRACT
Over the last decade much effort has gone into forming piezoelectric materials, eg lead zirconate titantate (PZT), on top of micromachined silicon to make sensors and actuators. However the techniques involved in making such devices are complicated and time consuming, reducing their commercial value. Large area silicon p—n and Schottky junctions have been chosen to demonstrate this effect, because they are considered to have well defined junction interfaces. An alternating potential and bias voltage applied across the junction interface would cause an alternating tension and thus a strain in the plane of the junction, so causing the cantilever to vibrate. Initially, experiments were performed with a bias voltage of 2 V over a range of frequencies to determine the frequency response of the cantilever. The experiments clearly show that silicon junctions are piezoelectric actuators, without the need for any additive piezoelectric material.
