Piezoresistance response of thin film manganin sensors

Thin film manganin sensors aimed at high-pressure measurement are prepared by DC magnetron sputtering. The structure and morphology of the films are analyzed by XRD and SEM techniques. The piezoresistance coefficient, k, is obtained through dynamic loading experiments. It is found that heat treatment leads to better manganin sensor piezoresistance response without manganese element volatilization. The experimental results show that annealing at higher temperature is helpful for the growth of larger size grains and decrease of defects in the thin films, this determining the improvement of k. The k of the thin films equals that of the foil-like.