Soft-bodied robots, due to their intrinsic compliance, have shown great potential for operating within unstructured environment and interacting with unknown objects. This letter deals with automatic design and fabrication of soft robots. From a structure point of view, we synthesize a soft cable-driven gripper by recasting its mechanical design as a topology optimization problem. Building on previous work on compliant mechanism optimization, we model the interactions between the gripper and objects more practically, in form of pressure loadings and friction tractions, and furthermore, we investigate how the interaction uncertainties affect the optimization solution by varying the contact location and area. The optimized soft fingers were three-dimensionally printed and then assembled to build a gripper. The experiments show that the gripper can handle a large range of unknown objects of different shapes and weights (up to 1 kg), with different grasping modes. This letter represents an important step toward leveraging the full potential of the freeform design space to generate novel soft-bodied robots.

Multimaterial soft robots, composing of integrated soft actuators and a relatively harder body, show great potential to exert higher payloads and support their own weights. This paper proposed a systemic framework to automatically design and fabricate this kind of robots. The multimaterial design problem is mathematically modeled under the framework of topology optimization in which the structure and material distribution are obtained simultaneously. Herein, a multimaterial pneumatic soft finger, modeled as a compliant mechanism, is optimized to achieve its maximal bending deflection and further customized to practical applications on grippers, rehabilitation and an artificial hand. These optimized multimaterial soft fingers are fabricated by combining molding and 3D printing technique. Experimental results show that the soft gripper can manipulate a large variety of objects with different shapes (from M4 screws to complicated sunglasses) and weights (up to 168g), the rehabilitation finger can facilitate human safely in two modes, and the artificial hand can perform various gestures. This work represents an important step toward the realm of high-performance soft robots.

Kirigami is the art of paper cutting, and it is emerging as an elegant design and manufacturing solution in mechanical metamaterials. Currently, the majority of kirigami designs focus on shape‐morphing, but there is little attention on the remarkable mechanical properties they can produce: high strength to weight ratio where they can bear thousands of times of their own weight. This paper proposes a kirigami‐based, strong, yet lightweight metamaterial, which is created by folding pop‐up and pop‐down from a checkerboard pattern with blocks. To transform the kirigami metamaterial into arbitrary objects, the challenge lies in how to automatically design the kirigami folding to approximate the outline of the object. Herein, a computational model that is based on deploying discretized objects onto a planar sheet is proposed. Additionally, to achieve high strength, a glue‐free connector that can lock the collocated cuts in the folded configuration is designed. The standard compression tests show that the kirigami metamaterial, weighing 12.05 g, can carry 346.4 N payloads. Meanwhile, six examples of curved surfaces are prototyped to verify the shape transforming capability of the proposed kirigami metamaterial. This study paves the way towards using the kirigami technique for weight reduction in industrial applications.