Piezoresistive Sensors: Strain Gauges

This lecture covers the principles of piezoresistive sensors, focusing on strain gauges. The instructor explains how metallic tracks deposited on polymer films are used to measure deformation in test bodies under external forces. Various factors affecting the resistance of wires subjected to deformation are discussed, including Poisson's ratio and electrical resistivity. Different types of strain gauge geometries and their applications are explored, along with considerations for wire elongation functions and thermal coefficients. The lecture also addresses issues such as creep, thermal drift, and noise in amplifier circuits for strain gauge measurements.