Transferable micromachined piezoresistive force sensor with integrated double-meander-spring system
A developed transferable micro force sensor was evaluated by comparing its response with an industrially manufactured device. In order to pre-identify sensor properties, three-dimensional (3-D) sensor models were simulated with a vertically applied force up to 1000 µN. Then, controllable batch fabrication was performed by alternately utilizing inductively coupled plasma (ICP) reactive ion etching (RIE) and photolithography. The assessments of sensor performance were based on sensor linearity, stiffness and sensitivity. Analysis of the device properties revealed that combination of a modest stiffness value (i.e., (8.19 ± 0.07) N m−1) and high sensitivity (i.e., (15.34 ± 0.14) V N−1) at different probing position can be realized using a meander-spring configuration. Furthermore, lower noise voltage is obtained using a double-layer silicon on insulator (DL-SOI) as basic material to ensure high reliability and an excellent performance of the sensor.