An ER Microactuator with Built-in Pump and Valve

The paper presents a 3-DOF microactuator having a Fluid Inertia (FI) micropump and ER microvalves for in-pipe working micromachines of about 10 mm in diameter, and so on. The ER microvalve controls an Electro-Rheological Fluid (ERF) flow due to the apparent viscosity increase in the electric field. The FI micropump generates high-output-fluid power using the fluid inertia effect in an outlet pipe. First, the 3-DOF ER microactuator with built-in pump and valves was proposed, and its construction was clarified. Second, in order to pump high viscosity fluids such as ERFs, a multi-reed valve was proposed for the inlet check valve of the FI micropump. The characteristics of the newly-devised pump were clarified through simulation and experiments. Then, based on the results, a 10 mm-diameter FI micropump was successfully developed. Finally, in the first stage of this study, a 1-DOF valve-integrated ER microactuator was designed and fabricated. The validity of the actuator with the fabricated 10 mm-diameter FI micropump was experimentally confirmed.