Advances in micro ultrasonic assisted lapping of microstructures in hard–brittle materials: a brief review and outlook

Micro ultrasonic assisted lapping was first proposed as an effective micromachining technique for hard–brittle materials by Masuzawa's group. Through applying innovative machine tool design concepts, holes as small as 5 μm in diameter and aspect ratios larger than five were machined in quartz glass and silicon. Further applications of the micro ultrasonic assisted lapping to generating microstructures in hard–brittle materials were extended by Brinksmeier's group, and path-controlled micro ultrasonic assisted lapping was implemented in LFM, University of Bremen. These excellent results have demonstrated a promising potential for practical, but the knowledge of micro ultrasonic assisted lapping is far from sufficient to provide a complete understanding and instructive rules for industrial users. The paper briefly reviews some new advances in micro ultrasonic assisted lapping, and then introduces some necessary research topics involved in the process in order to put it into practical microfabrication.