Abstract
This paper describes the design, manufacture, and evaluation of a capacitive pressure transducer made of polyimide films which is expected to provide robotic tactile imagers with structural flexibility and high sensitivity: The structure of a pressure transducer cell was first determined, followed by the analyses of the deflection-stress and capacitance-load characteristics of the surface film using finite element methods. In the practical stage of manufacture, a polyimide film was emboss processed and electrodes were deposited on the film to construct a capacitive transducer cell to which a Schmidt-trigger detecting circuit was connected. The operational characteristics of the cell were then examined to show that the actual relation between the deflection and load approximately agreed with the linear analyses and that the capacitance depended with little hysteresis on the gap regardless of the native visco-elasticity of the film, while the operation was stable below 50°C. It was also shown that small stick-slip vibration of a contact rubber surface could be detected by the transducer to verify its high sensitivity.
