Design and Online Calibration of a Highly Compact Microgripper

Microgrippers play a significant role in manipulation of micro-objects. To achieve dexterous and precise manipulation, a microgripper is required to be compactly designed and embedded with sensing feedback. Meanwhile, to convert the sensor position into displacement of the microgripper, the embedded sensors should be calibrated by additional equipment like laser sensor. However, a microgripper always needs to be calibrated during manipulation (online calibration), which is still a big challenge with current technology. In this paper, we proposed a highly compact microgripper integrated with position sensors, and a visual-based calibration method to handle such challenge. Moreover, to enhance grasping accuracy, flexure hinges are employed to achieve a low impedance grasping mechanism and to avoid the backlash in traditional bearing. Furthermore, kinematics analysis and Fine Element Analysis (FEA) are implemented to improve the design efficiency. Finally, fibrous micro-rings are successfully assembled, and the results reveal that the calibrated microgripper can be well employed to operate micro-objects.