Performance characterization of in-plane electro-thermally driven linear microactuators

Abstract

Static and dynamic electro-mechanical performance of a microactuator is a key factor in the functioning of an integrated microsystem composed of moving components such as optical shutters/switches, micropumps, microgrippers, and microvalves. Therefore, the development of such systems primarily focuses on the overall design and parameter optimization of an actuator as the major driving element with respect to the desired performance parameters, e.g., displacement, force, dimensional constraints, material, actuation principle, and method of fabrication. This study presents results on the static and dynamic electro-mechanical performance analysis of an in-plane electro-thermally driven linear microactuator. Each microactuator, having a width of 2220 mu m and made of 25 mu m thick nickel foil, consisted of a pair of cascaded structures. Connecting several actuation units in a series formed each cascaded structure. Several microactuators with a different number of actuation units were fabricated using the laser micromachining technology. The static performance of these microactuators was evaluated with respect to the maximum linear output displacements, actual resistance, applied current, and consumed electric power. The maximum displacements varied approximately from 3 to 44 mu m, respectively, depending on the number of actuation units. The dynamic performance was studied as a response function on constant applied current with respect to the output displacements. In addition, the response time was evaluated for different applied currents and for actuators with 2, 4, and 6 actuation units. The microactuators' performance results are promising for applications in MEMS/MOEMS, microfluidic, and microrobotic devices.