TABLE OF CONTENTS As we move into the third millennium, the number of microsensors evident in everyday life continues to increase. From automotive manifold pressure and air bag sensors to biomedical analysis, the range and variety are vast. It is interesting to note that pressure sensors and ink-jet nozzles currently account for more than two-thirds of the overall microtransducer market share. Future predications indicate that the mechanical microsensor market will continue to expand [1]. One of the main reasons for the growth of microsensors is that the enabling technologies are based on those used within the integrated circuit (IC) industry. The production cost of a commercial pressure sensor, for example, is around 1 Euro, and this is largely because the cost of producing ICs is inversely proportional to the volume produced. The trend in IC technology since the 1960s has been for the number of transistors on a chip to double every 18 months; this is referred to as Moore's law. This has profound implications for the electronic systems associated with microsensors. In addition to the reduction of size there is added functionality and also the possibility of producing arrays of individual sensor elements on the same chip.
Another feature that has influenced the popularity trend of microsensors is that many (but certainly not all) are based on silicon (Si). The electrical properties of silicon have been studied for many years and are well understood and thoroughly documented. Silicon also possesses many desirable mechanical properties that make it...
