Development of a compact displacement accumulation actuator device for both large force and large displacement

Abstract

The design, fabrication, and testing of a compact displacement accumulation device is presented in this paper. The piezoelectric device provides both large displacement (mm) and large force (100 N). The device is based on conventional inchworm motor design that produces large displacement. The device integrates piezoelectric stacks for large force output and high-speed operation with MEMS ridges as a new clamping system. The device should be able to push and pull 450 N at 11 mm/s in a relatively compact size. FEM analysis is used for the design, EDM is used for the fabrication of a prototype, and conventional test techniques are used to evaluate performance. Stress and modal analysis are used to confirm that the device has an infinite fatigue life and a first modal frequency at 1309 Hz. Experimental data for clamping strength of the ridges and blocking force of the device validate that the device transfers the required load of 450 N. The device is successfully tested over a wide range of operating conditions at speeds up to 11 mm/s using open loop control. The stall load of the device is measured to be exceeding 2250 N. For the dynamic loading test, the device pushes test weights up to 50 N with the open loop control approach.