Fabrication and Nonlinear Thermomechanical Analysis of SU8 Thermal Actuator

Viannie, Leema Rose and Jayanth, GR and Radhakrishna, V and Rajanna, K (2016) Fabrication and Nonlinear Thermomechanical Analysis of SU8 Thermal Actuator. In: JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, 25 (1). pp. 125-133.

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Abstract

SU8-based micromechanical structures are widely used as thermal actuators in the development of compliant micromanipulation tools. This paper reports the design, nonlinear thermomechanical analysis, fabrication, and thermal actuation of SU8 actuators. The thermomechanical analysis of the actuator incorporates nonlinear temperature-dependent properties of SU8 polymer to accurately model its thermal response during actuation. The designed SU8 thermal actuators are fabricated using surface micromachining techniques and the electrical interconnects are made to them using flip-chip bonding. The issues due to thermal stress during fabrication are discussed and a novel strategy is proposed to release the thermal stress in the fabricated actuators. Subsequent characterization of the actuator using an optical profilometer reveals excellent thermal response, good repeatability, and low hysteresis. The average deflection is similar to 8.5 mu m for an actuation current of similar to 5 mA. The experimentally obtained deflection profile and the tip deflection at different currents are both shown to be in good agreement with the predictions of the nonlinear thermomechanical model. This underscores the need to consider nonlinearities when modeling the response of SU8 thermal actuators. 2015-0087]

Item Type:	Journal Article
Publication:	JOURNAL OF MICROELECTROMECHANICAL SYSTEMS
Publisher:	IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
Additional Information:	Copy right for this article belongs to the IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 445 HOES LANE, PISCATAWAY, NJ 08855-4141 USA
Keywords:	SU8 thermal actuator; nonlinear thermomechanical analysis; 3D optical profiler; residual stress
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	06 Apr 2016 06:03
Last Modified:	06 Apr 2016 06:03
URI:	http://eprints.iisc.ac.in/id/eprint/53484

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