Mesoscale actuator device: Micro interlocking mechanism to transfer macro load

Abstract

A novel proof-of-concept prototype Mesoscale Actuator Device (MAD) containing microscale components has been developed. The MAD is similar to piezoelectrically driven inchworm motors with the exception that mechanically interlocking microridges replace the traditional frictional clamping mechanisms. The interlocked microridges, fabricated from single crystal silicon, are designed to increase the load carrying capability of the device substantially. Tests conducted on the current design demonstrate that interlocked microridges fabricated with 30% KOH solution support a 9.6 MPa shear stress or that a pair of 5×5 mm locked chips supports a 500 N load. For high frequency operation, an open loop control signal is implemented to synchronize the locking and unlocking of the microridges with the elongating and contracting of the actuator. The system was successfully operated from 0.2 Hz to 500 Hz (or speeds from 2 μ.m/s to 5 mm/s). The upper limit (500 Hz) is imposed by software and hardware limitations and not related to physical limitations of the prototype device.