Micro ER valve using homogeneous ER fluids and its application to micro fluid control system

To realize practical micromachines using fluid power with high power density, a micro fluid control system using homogeneous ER (electrorheological) fluids is proposed and fabricated. Homogeneous ER fluids such as nematic liquid crystals change their viscosity with applied electric field strength and is usable in micro flow channels without dispersed particles. Firstly, a micro ER valve using homogeneous ER fluids without moving parts is proposed and fabricated with 9 mm in diameter and 3 mm in thickness. Static and dynamic characteristics are investigated. Secondly, improvements of a piezoelectric micropump using resonance drive are experimentally investigated for pumping homogeneous ER fluids. The micropump has been proposed as a fluid power source for micromachines, fabricated with 9 mm in diameter and 10 mm in length and realized high output power density with low viscosity tap water Finally, an open-loop micro position control system is constructed with the micro fluid devices and one bellows microactuator Through basic experiments, the output displacement of 23 /spl mu/m and the bandwidth of 0.3 Hz are realized.