Development and Experimental Evaluation of a Vibration-Based Adhesion System for Miniature Wall-Climbing Robots

In recent years, miniature wall-climbing robots have attracted widespread attention due to their significant potential in equipment inspection and in-situ repair applications. Traditional wall-climbing systems typically rely on electromagnetic, electrostatic, vacuum suction, or van der Waals forces for controllable adhesion. However, these conventional methods impose limitations when striving for both a compact design and high-speed mobility. This paper proposes a novel Vibration-Based Adhesion (VBA) technique, which utilizes a flexible disk vibrating near a surface to generate a strong and controllable attractive force without direct contact. By employing an electric motor as the vibration source, the constructed VBA system was experimentally evaluated, achieving an adhesion-to-weight ratio exceeding 51 times. The experimental results demonstrate that this adhesion mechanism not only provides a high normal force but also maintains minimal shear force, making it particularly suitable for high-speed movement and heavy load applications in miniature wall-climbing robots.

Design, manufacturing, and inverse dynamic modeling of soft parallel robots actuated by dielectric elastomer actuators

Soft parallel robots with their manipulation safety and low commercial cost show a promising future for delicate operations and safe human-robot interactions. However, promoting the use of electroactive polymers (EAPs) is still challenging due to the under-improving quality of the product and the dynamic modelling of the collaborations between multiple actuators. This article presents the design, fabrication, modelling and control of a parallel kinematics Delta robot actuated by dielectric elastomer actuators (DEAs). The trade-off between the actuation force and stroke is retaken by an angular stroke amplification mechanism, and the weight of the robot frame is reduced by utilizing 3D puzzling strip structures. A generic way of constructing a high-stability conductive paint on a silicon-based film has been achieved by laser scanning the DE-film and then sandwiching a conductive particle-based electrode with a paint which is mixed by the particles and photosensitive resin. Compared to the wildly used carbon grease, the fabricated electrode shows a higher consistency in its dynamic behaviour before and after the on-stand test. Finally, to predict the output force and inverse motion of the robot end effector, we constructed the inverse dynamic model by introducing an expanded Bergstrom-Boyce model to the constitutive behavior of the dielectric film. The experimental results show a prediction of robot output force with RSME of 12.4% when the end effector remains stationary, and a well-followed trajectory with less than RSME 2.5%.