MEMS microgrippers with thin gripping tips

Gripping small objects requires tool tips of comparable dimensions. Current methods for miniaturizing an MEMS tool entirely down to sub-micrometer in dimensions, however, come with significant tradeoffs in device performance. This paper presents a microfabrication approach to selectively miniaturize gripping tips only to sub-micrometers in thickness. The process involves using the thin buried SiO 2 layer of a standard silicon-on-insulator wafer to form gripping tips, and using the thick device silicon layer to construct high-aspect-ratio structures for structural, sensing, and actuation functions. The microgrippers with thin gripping tips (i.e. finger-nail-like) were experimentally characterized and applied to gripping 100 nm gold spheres inside a scanning electron microscope.