Inertial sensors are designed to convert, or transduce, a physical phenomenon into a measurable signal. The physical phenomenon is an inertial force. Often this force is transduced into a linearly scaled voltage output with a given sensitivity. The methodologies used for macroscopic inertial sensors can and have been utilized for micromachined sensors in many applications. It is worth considering further what motivations have led to the introduction of micromachined inertial sensors. As will be demonstrated in this chapter, differences in accelerometer and gyroscopic application requirements do impact the choice of micromachining technology, transducer design and the system architecture. The definition of the system requirements often delineates micromachining technology options very clearly, although most sensing mechanisms and micromachining technologies have been applied to inertial sensors. First, design parameters will be reviewed for accelerometers. Accelerometers are the most straightforward inertial sensor system and will demonstrate the major physical mechanisms and micromachining technologies implemented to sense inertial displacement. Next, gyroscopic sensors, or sensors for rotational inertia, will be reviewed and will demonstrate how the technology can impact system and sensor, or transducer, design. Inertial device parameters are tightly coupled with lessons from Part I of this handbook, applying material from Chapters 2 to 5 by Trimmer and Stroud, Sharpe, Gad-el-Hak, and Kirby et al., in particular. A thorough background in micromachining technologies that have been implemented in micromachined inertial devices can be found in Part II of this handbook. Systems issues of inertial sensing tie in with the control theory discussions found in Chapters 12 and 13 by Goodwine and Bewley, respectively.
The MEMS Handbook
Bergstrom, P. L.,
Li, G. G.
The MEMS Handbook,
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