Lifting-Force Maximization of a Micropatterned Electroadhesive Device Comparable to the Human-Finger Grip

Electroadhesion device allows one to pick up almost all of the objects regardless of their shape or type of materials by means of the electrostatic Maxwell force, which is developed due to the dielectric-induced polarization on the subject surface. In this study, we propose the modeling methodology and its experimental verification that could maximize the lifting shear force of the electroadhesive device to reach well over the human-finger grip force, say, ca. 8.9 kPa, which has not been achieved yet in this device system. In this study, we maximized the lifting force up to 33.05 kPa for paper objects by scaling down the electrode pitches in the scale of micrometers while avoiding the voltage breakdown using the boundary-edge-length modeling methodology [ Choi, K.; et al. ACS Omega 2019, 4, 7994-8000]. The developed model equation expressed adhesion lifting force as a function of the boundary edge length, applied voltage, and impedance, demonstrating that the model equation agreed well with the experimental output of our device and allowed the lifting force well over the human-finger grip. The in situ charge-transfer resistance measurement value of the impedance analysis (RCT), indicating the amount of polarization, was decreased in the order of paper and glass, and it was clearly related to the enhanced lifting force of the two types of objects (23.9 and 50.0 kPa, respectively). Hence, the impedance analysis could quantify the magnitude of polarizations and the amount of induced charges of objects while in contact with the device.