Design of Chevron Electrothermal Microgripper and its Prototyping Using SLM Based Additive Manufacturing

Microelectromechanical systems (MEMS) are a key element contributing to major developments in modern science and technology. MEMS devices are capable of providing low-cost solutions to miniaturize a large number of devices. The increasing number of MEMS devices in specialized application areas demonstrates their influence in providing high-reliability solutions to meet demand. Micro-electrothermal grippers are the most prominent and attractive micro-actuating devices for producing displacement with high force for an applied electric potential. This work proposes an in-plane chevron actuator, operating on the principles of the joule heating effect and thermal expansion. In our previous work, we conducted electrothermal and thermomechanical analyses for the single-bent beam actuator design, and the obtained results aligned well with the simulation results using COMSOL Multiphysics. In this work, we extend the single-bent beam actuator to a microgripper by stacking the beams. The extended microgripper produces a maximum displacement of 25.5 μm at 0.12 V with a temperature of 569 K at the tip. An aluminum alloy, Al6061N, is chosen for the actuator because of its good thermomechanical properties. Rapid prototyping of a scaled-up model of the proposed microgripper is done through SLM (Selective Laser Melting) using aluminum alloy. The designed microgripper produces controlled actuation through an inner shuttle, which makes it suitable for manipulating micro-objects and biomanipulation applications.