Material-Driven Mechanical Programming of Soft Robotic Tentacles

Soft robotic grippers with stochastic and topological grasping capabilities can be highly desirable for gentle contact and interaction with fragile objects of various shapes. In this study, we developed soft tentacles using silicon elastomeric material with an embedded pneumatic channel, which generates desirable three-dimensional (3D) curling deformation under pneumatic pressure. Additionally, various ratios and geometrical distributions of two silicon materials, which differ primarily in stiffness, were investigated to determine their effect on grasping efficiency. The tentacle's grasping performance was systematically tested across multiple tentacle designs and grasping strategies. Results showed that optimizing the combination of softer elastomers with stiffer materials significantly improved the tentacle's ability to securely grip and carry loads while maintaining gentle contact with objects (up to 5 kg). The pneumatic tentacle's simple control mechanism and versatility in handling objects of various shapes and sizes offer a low-cost, adaptable solution for future applications in soft robotics.