Dynamic performance enhancement of PVDF force sensor for micromanipulation

Abstract

So far, in-situ PVDF (polyvinylidene fluoride) films bonded to the surface of flexible cantilever structure act as the micro-force sensors, they are mostly modelled using quasi-static relationships. However, such sensors are usually a significantly compliant and easily deformable structure in order to reach highly sensitive performance in micromanipulation. As a result, this may be reasonable to consider bandwidth measurement and high frequency response for achievement of high accuracy, and thus a dynamic analysis of such sensors become essentially necessary. In this paper, a cantilever beam based micro-force sensor was designed based on the infinite dimensional system model (distributed parameter model) using the Bernouli-Euler formulation. Furthermore, in order to enable an engineering implementation, we used a zero frequency term to effectively replace the high order modes of the dynamic sensing model in the prescribed frequency range. The corrected model can efficiently minimize the effect of removed higher order modes, and then the micro-force measurement can be obtained accurately with this corrected in-bandwidth dynamic model. Preliminary simulation and experimental results both verified the performance of the developed dynamic micro-force sensor and the effectiveness of the corrected model.