On the accuracy of an interdigital electrostatic position sensor

Abstract

In this work the induced voltage in an interdigital electrode when swept by a finite, triboelectrically charged dielectric surface is investigated. Finite element modelling fits well with the measured voltage as a function of position. An analytical model for the accuracy with which the position of the object can be determined, in presence of noise, is presented. The fundamental limit with which the position can be determined from electrical output data is also discussed, and could act as a useful guideline when estimating the limits of self-powered position sensor systems.