Mesoscale actuator device with micro interlocking mechanism

Abstract

A novel proof-of-concept prototype Mesoscale Actuator Device (MAD) has been developed. The MAD is similar to piezoelectric driven inchworm motors with the exception that mechanically interlocking microridges replace the traditional frictional clamping mechanisms. The interlocked microridges, fabricated from single crystal silicon, increase the load carrying capability of the device substantially. Tests conducted on the current design demonstrate that the interlocked microridges support 16 MPa in shear or that a 3/spl times/5 mm locked chip supports a 25 kgf load. To operate the MAD device at high frequencies an open loop control signal is implemented. Synchronizing the locking and unlocking of the microridges with the elongating and contracting actuator requires minor perturbations in the voltage signal supplied. The system was successfully operated from 0.2 Hz to 500 Hz (or speeds from 2 /spl mu/m/s to 5 mm/s). The upper limit (500 Hz) is imposed by software limitations and not related to physical limitations of the current device.