Micro fluid control system using homogeneous ER fluids (proposition of micro ER valve and basic experiments)

To realize practical micromachines using fluid power with high power density, a micro fluid control system using homogeneous ER fluid is proposed and developed. Firstly, a new micro ER (electrorheological) valve using homogeneous ER fluid is proposed and fabricated. Its diameter is 9 mm. Static and dynamic characteristics are investigated. With supply pressure of 25 kPa and electric field strength change of 1.0 kV/mm, it is ascertained that the controllable pressure range is 10 kPa and the bandwidth is 0.5 Hz. Secondly, output characteristics of a resonantly-driven piezoelectric micropump 9 mm in diameter and 10 mm long are experimentally investigated by using homogeneous ER fluid. Maximum flow rate of 15 mm³/s and maximum pumping pressure of 0.2 MPa are obtained. Finally, an open-loop micro position control system is fabricated, which consists of the micropump, the micro ER valve and a bellows microactuator. Through basic experiments, it is confirmed that the output displacement of 23 μm and the bandwidth of 0.3 Hz are realized