MEMS-based clamp with a passive hold function for precision position retaining of micro manipulators

Abstract

In this paper the design, modeling and fabrication of a precision MEMS-based clamp with a relatively large clamping force are presented. The purpose of the clamp is to mechanically fix a six-degree-of-freedom (DOF) MEMS-based sample manipulator (Brouwer et al J. Int. Soc. Precis. Eng. Nanotechnol. submitted) 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 mm 2 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 of Si x N y 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.

Design and modeling of a six DOFs MEMS-based precision manipulator

“…A second reason is, the manipulator can be switched between compliant actuation modes for positioning, and high frequent vibration modes during imaging. A clamping mechanism has been developed for this purpose [34]. In the final design a mechanical clamp with a locking device is integrated.…”

“…A mechanical clamping mechanism with a locking device can be integrated in the manipulator for that purpose [34]. Clamping also prevents the six low frequency vibration modes resulting from the compliance in the actuation direction of the folded flexures.…”

Design and Fabrication of a Planar Three-DOFs MEMS-Based Manipulator

“…A margin should be taken into account for the alignment error between the first and second mask. The fabrication rules for the insulation tranches is further discussed by Brouwer et al [6].…”

“…Apart from general accuracy requirements, applications as discussed earlier all have their specific specifications. Here, these are left out of scope, but Brouwer et al, for instance, discuss a passive clamping mechanism for position stability of a combdrive-actuated micromanipulator in a TEM [6].…”

Numerical Simulation of Arc and Metal Transfer in Arc Welding Based Additive Manufacturing Assisted by External Longitudinal Static Magnetic Field

“…Especially, the external longitudinal static magnetic eld (ELSMF) can induce EMS in arc welding deposition, which can reduce the height of weld bead as well as increase the width of weld bead, namely the increase of the aspect ratio (width-height ratio) of single weld bead. In the AWAM process, it has been demonstrated that parameter control is di cult to achieve the ideally at surface in overlapping deposition process, and the large aspect ratio is bene cial to improve the overlapping accuracy [11] . Furthermore, the transverse crosssection of weld bead assisted by longitudinal static magnetic eld is not symmetrical and tilt to one side due to the tangential-EMS and asymmetrical molten pool [12] .…”