Bioinspired Hybrid of Electrolysis and Fluidic Reaction (HEFR) Soft Actuator, Mimicking Natural Muscle Filament...

This study employs the hybrid of electrolysis and fluidic reaction (HEFR) technique to investigate an experimental soft actuator model designed as an artificial myosin. Energy is generated through chemical reactions involving acetic acid (CH₃COOH), bicarbonate (NaHCO₃), and water (H₂O), combined with chemical electrolysis, which powers the soft actuator to produce muscle-like movements. Conversely, when the actuator relaxes under external stimuli, it can generate an electric current. The performance of the artificial myosin was assessed through three test cases. In the first case, the actuator, designed as a simple expanding mechanism, unfolded under pressurized fluid, demonstrating its ability to push weights ranging from 0 to 500 g in approximately 1 s. Additionally, in relaxation mode, the actuator produced electricity (~0.5 mW). The second test case examined the reciprocating motion of two opposing artificial myosins. Using the asymmetric principle of folding lines for each myosin and an edged actin on one side, this configuration achieved a 15 mm contraction per cycle within 2 s while also generating electricity during relaxation. In the third case, multiple artificial muscles were incorporated, combined with the asymmetric principle and variations in actuator stiffness, enabling contractile movements and curved rotations that mimic natural myosin function. This research demonstrates that integrating chemical reactions, electrolysis, and multiple soft actuators while applying the asymmetric principle can replicate myosin contraction similar to natural muscle while also enabling energy harvesting. The proposed approach holds significant potential for further development and optimization across various applications.