Over the years there has been a growing interest in the field of low power miniature sensors and wireless sensor networks. One specific topic that has received little attention is how to supply the required electrical power to such sensors. Conventional power supplies external to such sensors is one way. However, many applications do require such sensors to be completely embedded in the structure with no physical connection to the outside world. Supplying power to such systems is difficult and as a result they need to have their own power supply unit making them self-powered microsystems. ...