Flexible displacement sensor using piezoelectric polymer for intelligent FMA

Recently, a variety of soft actuators have been developed. However, applicable sensors such as potentiometers and optical encoders generally have high stiffness. Therefore, a soft actuator loses its compliance when these sensors are used with the actuator. Thus, in this research, we have developed a flexible displacement sensor that can keep the compliance of a soft actuator. The fabricated flexible displacement sensor is composed of piezoelectric polymer, conductive paste and base rubber. Piezoelectric polymer: poly(vinylidene fluoride- trifluoroethylene) [P(VDF/TrFE)] was used for the detection of displacement and conductive paste was used for electrodes. An intelligent FMA (flexible microactuator) was developed by attaching these sensors. Displacement of the intelligent FMA and the sensor output voltage were compared, and sensing features were evaluated. Furthermore, servo control of the intelligent FMA using the sensor was performed. As a result, high positioning accuracy was verified.