SU-8 piezoresistive microcantilever with high gauge factor

Presented is an SU-8 microcantilever sensor with integrated piezoresistors made of a mixture of SU-8 polymer and silver nanoparticles. The resulting composite is a spin-coatable and ultraviolet patternable conductive polymer, which can be easily incorporated with any SU-8-based microdevice. The microfabrication technique used in this work is based on adhesive bonding of the cantilever layers with the thick support base to obtain a three-dimensional structures device, which is a cost-effective and fast fabrication process. Based on the current-voltage (I-V) test, the fabricated piezoresistors exhibit a linear resistance characteristic with good conductivity. The gauge factor calculated from the deflection test was obtained to be as high as 26.3, demonstrating the capability for embedded SU-8/Ag piezoresistors to improve sensitivity when using polymeric material as a sensor platform.