A MEMS microgripper with two-axis actuators and force sensors for microscale mechanical characterization of soft materials

• Published in: 2015 IEEE International Conference on Automation Science and Engineering (CASE) pp. 1620 - 1625
• Main Authors: Juntian Qu, Weize Zhang, Jung, Andrew, Cruz, Simon Silva-Da, Xinyu Liu
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.08.2015
• Subjects: Actuators; Capacitive sensors; Force; Force sensors; Grippers; Micromechanical devices; Testing
• DOI: 10.1109/CoASE.2015.7294332
• ISSN: 2161-8070

This paper reports a MEMS microgripper integrating two-axis actuators and force sensors for microscale compressive and shear testing of soft materials. Two V-beam electrothermal actuators are used to actuate an active gripping arm along two orthogonal directions and compress or shear a micro-sample grasped between the gripping tips, and two tri-plate differential capacitive sensors are employed for quantifying the compressive and shear forces applied to the sample with nanonewton resolutions (compressive force resolution: 7.7 nN and shear force resolution: 57.5 nN). Using the microgripper, we demonstrate, for the first time, on-chip compressive and shear testing of polydimethylsiloxane (PDMS) micro-structures prepared at different mixing ratios. This device will be useful for accurately characterizing compressive and shear properties of a variety of microscale soft materials.