ABSTRACT
In the past several decades, partly because o f the rapid development o f the m i croelectronics industry and the ever-increasing applications o f microcomputers and the automation o f various industries, demands for transducers (sen sors/actuators) have increased exponentially. This trend is expected to continue as global competition for higher productivity and better quality forces companies in every industry to be constantly looking for ways to reduce cost and improve the quality o f their production. In one respect, the revolution in microelectronics and computers has dramatically reduced the cost o f automation and control, and has therefore led to broad applications o f these technologies in areas where these tech nologies were not deemed to be economically feasible. On the other hand, the de velopments in the microelectronics industry and, more recently, the fast develop ment o f microelectromechanical systems (MEMS) , have generated a wide variety o f sensors and actuators at ever-lowering costs, therefore opening up opportunities for applications in some areas not feasible in the past. The fast development o f microelectronics has also dramatically improved signal processing and computa tion capabilities. A signal processing job that might have required a large box o f electronic components decades ago can now be carried out by a single IC chip. The availability, the simplicity, and the performance o f circuit modules such as active filters, analog dividers, sample/hold devices, function generators, lock-in amplifiers, etc., have made it very convenient to integrate sensors and actuators in a mechanical system and has made the lives o f application engineers much easier. As a consequence, integration o f sensors and actuators into a system and dealing with signal conditioning, work that was deemed to be the province o f an electrical engineer many years ago, can now be done by mechanical, c iv i l , or chemical en gineers. This helps expand further the application o f advanced sensors in industry.
