Active Connection Mechanism for Soft Modular Robots

To date, most modular robotic systems lack flexibility when increasing the number of modules due to their hard building blocks and rigid connection mechanisms. In order to improve adaptation to environmental changes, softness at the module level might be beneficial. However, coping with softness requires a fundamental rethinking of the way modules are built. A major challenge is to develop a connection mechanism that does not limit the softness of the modules, does not require precise alignment and allows for easy detachment. In this paper, we propose a soft active connection mechanism based on electroadhesion. The mechanism uses electrostatic forces to connect modules. The method is easy to implement and can be integrated in a wide range of soft module types. Based on our experimental results, we conclude that the mechanism is suitable as a connection principle for lightweight modules when efficiency over a wide range of softness, tolerance to alignment and easy detachment are desired. The main contributions of this paper are (i) the qualitative comparison of different connector principles for soft modular robots, (ii) the integration of electroadhesion, featuring a novel electrode pattern design, into soft modules and (iii) the demonstration and characterization of the performance of functional soft module mockups including the connection mechanism. © Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2012