Design and fabrication of PDMS-based electrostatically actuated MEMS cantilever beam

Abstract

Polymer microelectromechanical system (MEMS) devices emerge as the new class of sensor devices for bio-sensing applications exhibiting high mechanical deformability and sensitivity. In this work, the design and fabrication of electrostatically actuated polydimethylsiloxane (PDMS) MEMS cantilever on flexible PDMS substrate is presented. The physical parameters of the cantilever were analysed and optimised using Taguchi method coupled with COMSOL Multiphysics software. This work focusses on the development of a novel approach for the simple and cost-effective fabrication process of PDMS cantilevers and subsequently its arrays. The proposed device consists of a PDMS body with the metal bottom electrode, PDMS anchor, and PDMS cantilever beam as its top electrode and immobilization surface. The work presented is of the cracking phenomenon in the metal layer sputtered on the PDMS substrate. The novelty of the fabrication process is the use of low-cost processes, no need for sophisticated lithography tools or etching equipment. Also, the process allows the use of alternate material as base substrate (glass, silicon wafer etc.) wherein it is not consumed and is reusable. The fabricated device is then electrically characterised for its pull-in characteristics.