Soft Materials & Design
Materials composing soft robots are usually soft and compliant, whereupon they carry safety and adaptability for tasks at the human-robot interface and elsewhere. Development of material combinations and their architectures is an appealing challenge of soft, wearable robots. Our center provides a solution to this challenge by employing strategies of nanomaterials, structural design, and rigid-soft hybrid design.
Nanomaterials such as nanoparticles, nanowires, carbon nanotubes, and liquid metals can be functional bases of soft materials. We synthesize these nanomaterials, control their electrical, mechanical and optical properties, and pattern them into stretchable transparent conductors, touch pads, heaters, and other soft robot components, by leveraging state-of-the-art technologies including selective laser ablation, direct ink writing, 3D printing, and other solution/deposition processes.
Origami, the art of folding, is a promising platform that provides capabilities of deployment and body compliance to several parts of a robot. We develop various scales of assemblies, actuation and locking mechanisms, and bioinspired dual morphing capabilities of origami architectures. Representative achievements include a self-locking foldable robotic arm that achieves 17.5 times length extension and 200 times larger resistance to compression, and a new architecture of deployable soft robots that can first unfold and then stretch in response to fluidic pressure like the design and morphing principle of the biological analog, Eurypharynx pelecanoides (commonly known as the pelican eel).
Compliant bodies consisting of rigid-soft hybrid structures have versatility in stiffness engineering and unfamiliar mechanical responses. Using this hybrid concept, we develop hybrid pneumatic networks, auxetic elastomer patches, and various jamming mechanisms for reconfigurable variable stiffness, including tendon-driven jamming and sliding linkage-based layer jamming. These technologies demonstrate multiple applications for soft sensors and wearable robots.