Pneumatic Soft Robots Research Articles

New soft robots really suck: Vacuum-powered systems empower diverse capabilities.

We introduce a vacuum-powered soft pneumatic actuator (V-SPA) that leverages a single, shared vacuum power supply and enables complex soft robotic systems with multiple degrees of freedom (DoFs) and diverse functions. In addition to actuation, other utilities enabled by vacuum pressure include gripping and stiffening through granular media jamming, as well as direct suction adhesion to smooth surfaces, for manipulation or vertical fixation. We investigate the performance of the new actuator through direct characterization of a 3-DoF, plug-and-play V-SPA Module built from multiple V-SPAs and demonstrate the integration of different vacuum-enabled capabilities with a continuum-style robot platform outfitted with modular peripheral mechanisms. We show that these different vacuum-powered modules can be combined to achieve a variety of tasks-including multimodal locomotion, object manipulation, and stiffness tuning-to illustrate the utility and viability of vacuum as a singular alternative power source for soft pneumatic robots and not just a peripheral feature in itself. Our results highlight the effectiveness of V-SPAs in providing core soft robot capabilities and facilitating the consolidation of previously disparate subsystems for actuation and various specialized tasks, conducive to improving the compact design efficiency of larger, more complex multifunctional soft robotic systems.

Exo-Glove PM: An Easily Customizable Modularized Pneumatic Assistive Glove

Customization is an important issue for assistive gloves because it affects glove performance. In this letter, we propose an assembly based customizable soft pneumatic assistive glove, named Exo-Glove PM. Pneumatic soft robots generally consist of a single structure with embedded actuators. However, when assembled, the region where the assemblies are connected easily undergoes large stress concentration that leads to failure. To overcome this issue, we have developed a hybrid actuator module that combines a soft actuation structure and rigid joining methods. In general, rigid joining methods require a bulky design to enable easy assembly, but Exo-Glove PM is designed to create pathways for assembly tools to access the bolt heads by bending certain parts. This novel way of joining assemblies allows soft robots to be built of multiple parts while minimizing the volume. It ensures small module size and enables modules to cover a wide range of hand sizes; the distance between each module is matched to the length of the user's phalanges using spacers. This approach allows users to customize the glove by assembly of standardized modules and maximizes the comfort and the performance of the glove without custom manufacturing and, thus, reduces costs.

A Miniature Soft Robotic Manipulator Based on Novel Fabrication Methods

Flexible robotic manipulators have been widely used in minimally invasive surgery (MIS) and many other applications requiring closer inspection and operation. Although a variety of manipulators enabled by different mechanism have been developed, few of them can preserve softness, thinness, and decent bending capability simultaneously. In this letter, we present a miniature soft robotic manipulator made of hyper-elastic silicone rubber. Along with the manipulator design, two novel fabrication methods are proposed and elaborated. Detailed characterizations are specified to show the bending capability of the manipulator given different air pressure. Specifically, our manipulator, as thin as 6 mm, is able to achieve 360° directional bending, and, when given pressure over 70 kPa, it can reach 180° bending angle and around 5 mm bending radius easily. Due to its innate compliance and small dimension, this type of robotic manipulator can deliver safe and comfortable interactions with the subjects. More significantly, the novel fabrications in this letter diversify the fabrication methods for soft pneumatic robots and actuators (SPRA) and further scale down their sizes.