On Teaching The Operating Principles Of Piezoresistive Sensors

We present an approach to teaching the operating principles of piezoresistive sensors that addresses many of the limitations of the treatments encountered in most instrumentation and MEMS textbooks. Namely, we direct the presentation to an undergraduate audience rather than a research-level audience and at the same time we avoid oversimplifying the development of the principles of operation. To this end, we make a discussion of bridge analysis central to the development, use a strain-formulation for gage factor and piezoresistor placement rather than the more common stress-formulation, and keep the associated physics and mathematics at an appropriate level for sophomore engineering undergraduates. In so doing, we maintain accessibility and coherence throughout. We present several sets of learning objectives and strategies for teaching the material that can be tailored to suit the needs of a particular course.