Transforming Soft Robotics: Laminar Jammers Unlocking Adaptive Stiffness Potential in Pneunet Actuators

Abstract

PneuNet actuators emulate human finger function and have broad application potential in domestic and industrial settings. To unlock their full potential, enhancing their controlled stiffness is crucial. This study presents the innovative design, fabrication, and evaluation of a cost-effective soft hybrid bending actuator by merging a homogeneous laminar structure, composed of 75 GSM printer paper, with a PneuNet actuator produced through soft lithography techniques. This research also characterizes the ensemble based on its tunable stiffness properties and examines the friction tests on jamming layers, highlighting the stabilization of frictional properties over time, which is critical for achieving consistent tunable stiffness. Experiments revealed that the actuator’s resistive force increases due to deformation when subjected to an external load. Furthermore, this linear rise in resistive force can be modulated through the use of an integrated laminar jammer by adjusting the vacuum pressure. Results reveal a negligible stiffness increase beyond −53.33 kPa of vacuum pressure, signifying an ideal vacuum pressure limit for energy conservation during vacuum jamming. A maximum stiffness of 0.116 N was achieved at −80 kPa of vacuum pressure. This study propels the field of soft robotics by offering enhanced tunable stiffness characteristics for diverse applications.