MEMS-based clamp with a passive hold function for precision position retaining of micro manipulators
The goal was to design, model and fabricate a precision MEMS-based clamp with a relatively large clamping force. The purpose of the clamp is to mechanically fix a six degrees of freedom (DOFs) MEMS-based sample manipulator once the sample has been positioned in all DOFs. The clamping force is generated by a rotational electrostatic comb-drive actuator and can be latched passively by a parallel plate type electrostatically driven locking device. The clamp design is based on the principles of exact constraint design, resulting in a high actuation compliance (flexibility) combined with a high suspension stiffness. Therefore, a relatively large blocking force of 1.4 mN in relation to the used area of 1.8 mm2, is obtained. The fabrication is based on silicon bulk micromachining technology and combines a high aspect ratio deep reactive ion etching (DRIE), conformal deposition of low pressure chemical vapor deposition (LPCVD) silicon nitride and an anisotropic potassium hydroxide (KOH) backside etching technology. Special attention is given to void-reduction in SixNy trench isolation and reduction of heating phenomena during front side release etching. Guidelines are given for the applied process. Measurements showed that the clamp was able to fix, hold and release a test actuator. The dynamic behavior was in good agreement with the modal analysis.
Duration : 0:0:59
Filed Under: MEMS
About the Author: