Towards fully optimized conducting polymer bending sensors: the effect of geometry
Conducting polymer devices have been demonstrated to generate a current or voltage in response to a displacement or force, which facilitates their use as mechanical sensors. Trilayer bending sensors are laminated conducting polymer devices that can provide self-contained operation in air, while maintaining many of the desirable conducting polymer properties including low weight and biocompatibility. This paper extends our previous characterization work by identifying the frequency response of the sensor output as the device geometry is varied and at frequencies up to 300 Hz. Current output is found to increase with the volume of conducting polymer across the sensor spectrum, while the usable sensor bandwidth is bounded by low-pass behaviour and a peak at the low frequency end of the spectrum and by a mechanical resonance at high frequencies. On the basis of these findings, suggestions are presented which can be used to optimize the current output and bandwidth of trilayer bender sensors.