A novel soft microgripper using divided-electrode type flexible ER valves

For maintenance microrobots for small diameter pipes in power plants and so on, a novel microgripper using divided-electrode type flexible electro-rheological valves (DE-FERVs) was proposed and developed. Each bendable finger consisted of the DE-FERV and a hydraulic rubber actuator and was several millimeters long. The DE-FERV had an axially divided parallel plate electrode pairs in a flexible tube. Each parallel plate electrode pair controlled the electro-rheological fluid (ERF) flow by changing the viscosity with the electric field. The DE-FERV had both high flexibility and sufficient pressure control range. The hydraulic rubber actuator had plural integrated walls inside to restrict its radial expansion and axially extended by the inner pressure controlled by the DE-FERV. A finger large model was fabricated and experimentally characterized. Then, a gripper having two fingers was constructed and the object handling was demonstrated.