Page 20 - Microsensors, MEMS and Smart Devices - Gardner Varadhan and Awadelkarim

INTRODUCTION

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Figure 1.1 Moore's law for integrated circuits: exponential growth in the number of transistors
in an 1C during the past 30 years

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Figure 1.2 Size of memory chips (DRAM) and minimum feature as a function of time. From
Campbell (1996)

1.2 EVOLUTION OF MICROSENSORS

The microelectronics revolution has led to increasingly complex signal-data proces-
sing chips; this, remarkably, has been associated with falling costs. Furthermore, these
processing chips are now combined with sensors and actuators 2 to make an information-
processing triptych (see Figure 1.3). These developments follow the recognition in the

2
A sensor is a device that normally converts a nonelectrical quantity into an electrical quantity; an actuator is
the converse. See Appendix C for the definition of some common terms.