A measuring method for micro force based on MEMS planar torsional spring

Abstract

In order to measure the micro force in a micro-nano device, a new measuring method for micro force is introduced. In this paper, a measuring system based on a micro-electro-mechanical systems (MEMS) planar torsional spring is presented, which contains a support block, MEMS planar torsional spring, a support arm, and a laser displacement detection system. The micro force has been obtained by measuring the moving distance of the light spot which is reflected by the MEMS planar torsional spring. The spring sample has been prepared with laser processing technology, and the stiffness is obtained by theoretical calculation, simulation, and calibration. The results show that the torsional stiffness of the MEMS planar torsional spring is 3.7181 Nm rad−1. The measurement system has a measuring range of ±159 mN. The maximum error of mean in repeated measurement is 1.25% of the reference value, and the repeatability standard deviation is a maximum 4.44% of the reference value.