Development of intelligent FMA by using paste injection (1st Report, fabrication of flexible displacement sensor with conductive paste and FMA using the sensor)

Recently, practical use of soft actuators is expected in the field of welfare robot. However, feedback control system for soft actuator has not been realized because appropriate sensor did not exist. Potentiometers or optical encoders which are generally used as displacement sensors have high stiffness and such sensors diminish the compliance of soft actuator. This paper presents fabrication of flexible displacement sensor and FMA (Flexible Microactuator) using this sensor. The flexible displacement sensor was fabricated by depositing conductive paste on the surface of rubber. A paste injection system was utilized to deposit the paste and it realized precise control of thickness, width and pattern of the film. Firstly, an experiment on flat type flexible displacement sensor was carried out to evaluate and improve the sensor. The experimental result showed enough linearity and detecting range. Then Intelligent FMA was fabricated by depositing conductive paste on the surface of FMA. Servo control system for Intelligent FMA was set up and high positioning accuracy was confimed by servo driving experiment.