Flexible displacement sensor using injected conductive paste

This paper reports on the fabrication procedure and the evaluation of a sensor with a flexible structure. Recently, because welfare robots with soft structures are being developed, there has been considerable progress in developing various soft actuators. Usually, however, sensors have high stiffness and diminish the compliance of soft actuators. In this study, a soft actuator's displacement was detected with a flexible displacement sensor using deposited conductive paste film. When the film was deformed, the sensor's electrical resistance changed, making a large deformation detectable. Initially, a flat type displacement sensor was fabricated, and its basic characteristics were evaluated. Then, an optimal wave patterning method that improved on the sensor signal's linearity was proposed. Finally, the flexible displacement sensor was formed onto the surface of a flexible microactuator (FMA). A servo control for the soft actuator was constructed with the flexible displacement sensor and high positioning accuracy was demonstrated.