Paper Based Piezoresistive Sensor Using MEMS

Abstract: This paper describes the development of MEMS force sensors constructed using paper as the structural material. The working principle on which these paper-based sensors are based is the piezo-resistive effect generated by conductive materials patterned on a paper substrate. The device is inexpensive (∼$0.04 per device for materials), simple to fabricate, lightweight, and disposable. Paper can be readily folded into three-dimensional structures to increase the stiffness of the sensor while keeping it light in weight. The entire fabrication process can be completed within one hour without expensive clean room facilities using simple tools (e.g., a paper cutter and a painting knife). In this project demonstrated that the paper-based sensor can measure forces with moderate performance. In this project applied this sensor to characterizing the mechanical properties of a soft material. The design of MEMS based piezo-resistive cantilever was made using COMSOL multi physics software version 5.0, in which the free end of the beam gets displaced when input pressure is applied. Five piezo- resistive materials are used. Copper, Silver, Graphite, Al2O3, Aluminium are analysed by varying input load. The work is concentrated mainly on the maximum amount of displacement observed for the applied pressure as a result of piezo resistive effect. Among the two materials considered, the material resulted in greater displacement for proposed geometry is Al2O3. When compared with other materials Al2O3 has low value of Young’s modulus and considerably high value of Poisson ratio.

Keywords: Piezo resistive sensor, MEMS