A pioneering work in micro-electromechanical system (MEMS) in 1954 by Smith [142] described stress-sensitive piezoresistive effects observed in silicon and germanium. Subsequently, a series of researchers in the 1960s published their findings on the first silicon diaphragm pressure sensors and strain gauges [117], [151]. Interest in silicon sensor technology grew dramatically. Waggener demonstrated deep silicon etching in 1967, [155] and the first mechanically enabled micro device based on bulk micromachining technology, a micro pressure sensor, was developed in 1970, by HP. This was followed by micromechanical nozzles for inkjet printer in 1979. The first micro engine based on surface micromachining was developed at Sandia National Laboratories, by Tanner [149], [116]. This was followed by a wide range of micro mechanical sensors and actuators, in a variety of applications in engineering, medicine and other fundamental sciences.