Design and test of reliable, high strength, ingressive polycrystalline silicon microgripper arrays

Published

January 2, 2015

Author(s)

Siddharth Hazra, Jack L. Beuth, Grant A. Myers, Frank W. DelRio, Maarten de Boer

Abstract

We present the design and extensive validation of a micromachined gripper array that enables reliable transmission of forces up to 10 milliNewtons. The gripper is constructed with polycrystalline silicon, a brittle material. Two ingressive snap-and-lock designs are presented. After developing design guidelines, it is shown that the first array is functional and yields strength data in good agreement with published literature. However, a risk remains that the gripper array rather than the tensile bar fails. Therefore, an improved geometry is designed and it is shown using statistical strength testing that it is robust with respect to failure. Scanning confocal Raman imaging directly confirms that the local peak tensile stresses in the robust gripper array are approximately 40 % of the lower bound material strength, and also resolves a small stress variation across the array.

Citation

Journal of Micromechanics and Microengineering

Volume

25

Pub Type

Journals

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Keywords

microgripper array, snap-fit latch, MEMS reliability, confocal Raman imaging

Citation

Hazra, S. , Beuth, J. , Myers, G. , DelRio, F. and de Boer, M. (2015), Design and test of reliable, high strength, ingressive polycrystalline silicon microgripper arrays, Journal of Micromechanics and Microengineering, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=916443 (Accessed February 8, 2025)