Use of PneuNets for Soft Robotic Rehabilitation Glove from Silicon Rubbers – A Computational and Experimental Investigation

PneuNets (Pneumatic Networks) actuators have gained recent attention in developing actuation systems for Soft Robotic Exoskeletons (SREs), which are serially connected air chambers that are pressurized during actuation. This research aims to investigate the suitability of several popular and widely available silicon rubbers (Silastic RBL-9200-30, Hydrogel, Elastosil 3000–60, Polyethylene Glycol 400, Sylgard184 (Dow corning silicone), and Ecoflex 00–30) to develop a soft robotic rehabilitation glove for flexion movement of the thumb using PneuNets actuators. Followed by a computer simulation study, we found that Silastic RBL-9200-30, Sylgard184 (Dow corning silicone), and Ecoflex 00–30 are best suited to fabricate actuators via 3-D moulding. Compared to 3-D moulds of the same dimensions, Ecoflex 00–30 3-D mould is the best considering low air bubble formation and fixing time of the structure. The soft robotic rehabilitation gloves developed using these three actuators were benchmarked for their flexion angle and actuator pressure and compared against clinical data and reported literature. We report that Ecoflex 00–30 actuators are best suited to develop soft robotic rehabilitation gloves as they agree well with clinical requirements and exhibit comparatively low internal pressures for flexion angle range 30 - 180°.