Yohta Yamamoto

Novel design of rubber tube actuator improving mountability and drivability for assisting colonosocope insertion

Recently, colonoscopy has become much more important with increasing number of colonic diseases. However, the inspection time depends on the doctors skill strongly.

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.

Evaluation of electro conductive film and strain gage as displacement sensor for pneumatic artificial muscle

For safety contact between humans and machines, Soft actuators are very useful. This reason is that soft actuators have flexibility, light weight and safety. However, it is difficult to realize accuracy control. The aim of this research is to develop a pneumatic soft actuator that has a flexible displacement sensor. The soft actuator is a pneumatic artificial muscle that can generate contracting motion. It consists of a silicone rubber tube and PET plates. Additionally it has a displacement sensor on constructional material. In this research, we have verified two types of sensors, strain gages and conductive film sensors. The both sensors can detect the change of their electrical resistance when the PET plate in the actuator is deformed. Through the experiments we have compared with each sensors feature.