Characterisation of PZT thin film micro-actuators using a silicon micro-force sensor
Date
Supervisor/s
Journal Title
Journal ISSN
Volume Title
Publisher
Department
Type
ISSN
Format
Free to read from
Citation
Abstract
This paper reports on the measurements of displacement and blocking force of piezoelectric micro-cantilevers. The free displacement was studied using a surface profiler and a laser vibrometer. The experimental data were compared with an analytical model which showed that the PZT thin film has a Young's modulus of 110 GPa and a piezoelectric coefficient d31,f of 30 pC/N. The blocking force was investigated by means of a micro-machined silicon force sensor based on the silicon piezoresistive effect. The generated force was detected by measuring a change in voltage within a piezoresistors bridge. The sensor was calibrated using a commercial nano-indenter as a force and displacement standard. Application of the method showed that a 700 μm long micro-cantilever showed a maximum displacement of 800 nm and a blocking force of 0.1 mN at an actuation voltage of 5 V, within experimental error of the theoretical predictions based on the known piezoelectric and elastic properties of the PZT film.