Development of Mesoscale Actuator Device with Microinterlocking Mechanism

A novel proof-of-concept prototype Mesoscale Actuator Device (MAD) is described in this paper. 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, microfabricated from single crystal silicon, are shown to support macroscopic loads with exact values dependent upon manufacturing processes. Tests conducted on the current design demonstrate that the interlocked microridges support 16 MPa in shear or that two sets of 3 x 5 mm locked chips support a 50 kgf. Operation of a prototype MAD device containing microridges is accomplished at relatively large frequencies using an open loop control signal. Synchronizing the locking and unlocking of the microridges with the elongating and contracting actuator requires a dedicated waveform in the voltage signal supplied and permitted large operational frequencies. The system was successfully operated from 0.2 Hz to 500 Hz corresponding to speeds from 2,um/s to 5 mm/s. The upper limit (500 Hz) was imposed by software limitations and not related to physical limitations of the current device.