Development of Metallic Digital Strain Gauges

Abstract

A joint Brunel-Southampton Universities’ research team has developed digital strain gauges based on a metallic triple-beam resonator structure with thick-film piezoelectric sensor elements. The resonator, an oscillating structure vibrating at resonance, is designed such that its resonant frequency is a function of the measurand. The resonator substrate was fabricated by a double-sided photochemical etching technique and the thick-film piezoelectric elements were deposited by a standard screen-printing process. The new metallic digital strain gauges can be used on stiff structures, have high overload capacities, low power consumption, frequency output for digital processing, and offer prospects for wireless-batteryless operation. The device can be easily mass-produced at low cost for use in a wide range of measuring systems, e.g. load cells, weighing machines, torque transducers and pressure sensors.