Parylene cantilevers integrated with polycrystalline silicon piezoresistors for surface stress sensing

Abstract

Polymer based microcantilevers are known to have higher sensitivity than their silicon counterparts for surface stress sensing, owing to the lower Young’s modulus of polymers. This letter reports the development of parylene cantilevers integrated with polycrystalline silicon piezoresistors for the detection of chemical or biological molecules based on the surface stress sensing principle. The justification of using parylene is presented with theoretical calculations along with finite element simulation. The fabrication process employed for making these devices is also reported. The functionality of the sensor was preliminarily proven by the detection of octanethiol vapors. The stability of the sensor in water was demonstrated as well.