Manufacturing and experimental characterization of electro adhesive devices

Electro Adhesive Devices (EADs) are innovative actuators deployable for many applications, such as robotic grippers, locomotion systems for climbing and crawling robots, haptic devices, and gadgets for space applications. The most relevant advantageous features of EADs are the low energy consumptions and the lightweight and compact embodiment. An EAD always includes an electrode couple and one or more dielectric layers, which host and insulate the electrodes. The working principle is based on the electrostatic attraction that takes place between the device and the object once the electrodes are connected to a voltage source, propagating an electric field. Due to the high dependency of the phenomenon on a huge number of physical variables, an analytical approach for estimating EAD performance is always complex. Therefore, an experimental approach leading to the definition of empirical models seems to be the most effective way for the evaluation of the performances and to address the design and fabrication process of EADs.This thesis proposes the Drop on Demand (DoD) Inkjet printing as the manufacturing method for the electrodes. A statistical systematic methodology based on Design of Experiment and ANOVA validates DoD Inkjet for the specific application by correlating the printing parameters to the geometry quality. An experimental characterization is carried out on EAD of two different types, one having PEEK and another having Polyimide (PI) thin films as the adhering surface, which also act as the electrode printing substrate. For PI-based EADs, an explanatory gripper prototype was developed. The characterization process assesses the Electro Adhesive Shear Stress (ESS) performance of such devices on different adhering materials, along with their consumptions and time responses during the gripping tests. Due to its high ESS results, PI-based EADs have been subjected to a manufacturing optimization process aiming to further increase adhesive force performances and dielectric strength.