Mesoscale actuator device: micro interlocking mechanism to transfer macro load

A novel proof-of-concept prototype Mesoscale Actuator Device (MAD) containi ng microscale components has been developed. The MAD is similar to piezoele ctrically driven inchworm motors with the exception that mechanically inter locking microridges replace the traditional frictional clamping mechanisms. The interlocked microridges, fabricated from single crystal silicon, are d esigned to increase the load carrying capability of the device substantiall y. Tests conducted on the current design demonstrate that interlocked micro ridges fabricated with 30% KOH solution support a 9.6 MPa shear stress or t hat a pair of 5 x 5 mm locked chips supports a 500 N load. For high frequen cy operation, an open loop control signal is implemented to synchronize the locking and unlocking of the microridges with the elongating and contracti ng of the actuator. The system was successfully operated from 0.2 Hz to 500 Hz (or speeds from 2 mu m/s to 5 mm/s). The upper limit (500 Hz) is impose d by software and hardware limitations and not related to physical Limitati ons of the prototype device. (C) 1999 Elsevier Science S.A. All rights rese rved.