Microgripper Based on Simple Compliance Configurations, Improved by Using Parameterization

Abstract

The design of a novel electrothermal microgripper device is shown, which is based on an improved chevron type actuator developed considering their elements parameterization, whose resistive model is also provided. The performance of the microgripper’s parameters, such as displacement, force, and temperature distribution, with convection for the voltage range from 0 up to 5 V, is evaluated through numerical and analytical simulation. Microgripper design was also improved with aid of parameterization. The effect on the microgripper performance due to its thickness is also analyzed, finding a considerable increment in force, when thickness increases. Its main advantage is given by the simplicity of the compliance arrangement of the microgrippers jaws. Considering convection, when 5 V are applied, 37.72 °C was generated at the jaw’s tips of the Improved Microgripper 2 (IMG2), implemented with silicon, this relatively low temperature increases its capabilities of application. When the IMG2 is implemented with polysilicon, its response is competitive comparing with a more complex microgripper, increase of displacement (50%) is shown, but a decrement of force (30%). The diameters allowed for the subjection objects are found between 84.64 µm and 108 µm, with weights lower than 612.2 µg. Some tests of subjection were performed using microcylinders of Au, glass ceramic, polycarbonate and carbon fiber, showing a permissible stress on them, considering its Young’s modulus, as well as the total reaction force induced. All simulations were done on Ansys software. The results demonstrate the feasibility of the future microgripper fabrication.

Keywords

• parameterization
• compliance arrangement
• displacement
• temperature distribution
• force
• silicon