Design of an Electrothermally Actuated SU-8 Based Microgripper for Biomedical Applications

Micromanipulation has become a significant task in the fields of microelectromechanical systems, cell biology and cell mechanics in past few decades. To study cell mechanics and cell biology, samples are required. In general, these samples are taken with the help of a microgripper, also known as micro-tweezer and micromanipulator. In this paper, a biocompatible microgripper design is presented for single cell manipulation. SU-8 material is selected due to biocompatibility and thermal properties for microgripper design. Electrothermal actuators are used to provide input displacement and force to compliant mechanism. Compliant mechanism include Scott Russell mechanism, Multi-stage Compound Radial Flexure and leverage mechanism, which provide amplification in output displacement at low power. Response of microgripper is close to linear for accurate and intelligent manipulation task. Jaws are designed to grip cells and objects of various shapes and sizes. Results are produced using finite element analysis software, to check the usability of design for biomedical applications. 30 mu m displacement is achieved at low voltage of 50 mV, keeping temperature of gripping jaws at room temperature.