High Bandwidth Microgripper With Integrated Force Sensors and Position Estimation for the Grasp of Multistiffness Microcomponents

At the microscale, small inertia and high dynamics of microparts increase the complexity of grasping, releasing, and positioning tasks. The difficulty increases especially because the position, the dimensions, and the stiffness of the micropart are unknown. In this paper, the use of a microgripper with integrated sensorized end effectors with high dynamic capabilities is proposed to perform stable and accurate grasps of multistiffness microcomponents. A dynamic nonlinear force/position model of the complete microgripper while manipulating a microcomponent is developed. The model takes into consideration not only free motion and constrained motion, but also, contact transitions which is a key issue at the microscale due to the predominance of surface forces. It enables us to estimate the position of the microgripper's end effectors, the contact position of the microcomponent, and the force applied on the microcomponent. Using the proposed microgripper and its model, both of the gripping forces are measured and the position of each of the microgripper's end effectors is estimated. This enables to perform a stable grasp of the micropart by providing force and position feedback. Moreover, using the developed microgripper and its model, the characterization of the microcomponent can be performed by estimating its dimensions and its stiffness.