Piezoresistive performance of load sensor based on ZnO film deposited on metal substrate
We report on the piezoresistive performance of zinc oxide (ZnO) thin films for applications in devices such as load cell and strain sensors. ZnO thin films were deposited on stainless steel (ZnO/SS) and aluminum substrates (ZnO/Al) using spray pyrolysis. Raman spectroscopy confirmed the growth of ZnO with wurtzite structure on both metal substrates. Results from the reflectance spectroscopy show that ZnO film grown on aluminum sheet is smoother compared to the film grown on stainless steel. Using a center load cantilever setup, the room temperature piezoresistive response of ZnO/Al was observed to increase linearly from load masses 10g to 90g. On the otherhand, the ZnO/SS only exhibited the linear response at 100g to 300g.