Meso-Scale Piezoelectric Gripper with High Dexterity

Design, fabrication and testing of a piezoelectrically actuated meso-scale dexterous gripper are reported. The gripper utilizes a piezoelectric ringmorph, which is excited by means of quarterly separated electrodes yielding 3 degree of freedom (3-dof) motion. Utilizing a specially designed arm, the 3-dof ringmorph actuation is transformed into a gripper motion bearing high dexterity. The combination of in-and out-of-plane motion unique to the gripper generates the herein explained sliding grip release, which improves the pick-and-place performance by avoiding sticking of the substrate. The 27 x 20 x 7 mm(3) gripper can generate 300 mg gripping force while it has 110 mu m out-of-plane and 30 mu m in-plane no-load maximum stroke at +/- 100V DC. The characterization of the device, including hysteresis and transient response are implemented as a function of loading condition and change in field intensity. The experimental results and sample pick-and-place tests have shown prominent force, stroke and frequency bandwidth of the gripper with a novel releasing method. (C) 2009 The Japan Society of Applied Physics