IPMC microgripper research and development

Abstract

Described are the state of the art on designing and developing a microgripper using ionic polymer metal composites (IPMCs), an electroactive material, as an actuator to grasp and manipulate micro-sized flexible and rigid objects and yet also serve as a sensor for position feedback control. IPMCs, as a material, are compliant and can work in both wet and dry environments. This makes it ideally suited for both industrial operations, e.g., building microsystems from MEMS components, as well as for a variety of bio-micromanipulation tasks, e.g., bacterium and cell handling. We derive a theoretical force model for the microgripper. The model estimates that an IPMC finger of dimensions 5mm × lmm × 0.2mm exerts a force of 85 μN when grasping a solder ball of 15mg. We experimentally measure the load carrying capacity of the IPMC microgripper. Furthermore, we show empirically that the relationship between load carry capability and the length of microgripper fingers is linear. Experiments with three different microgripper finger shapes show that load carrying performance is related to the area of the finger rather than the shape. This implies that manufacturing ease favours microgrippers with tapered fingers. Finally, we show how flexible objects (hydrogel crystals in this case) are grasped with this IPMC microgripper. © 2008 IOP Publishing Ltd.