Shape Morphing Robotic Surface

Many living organisms are able to accomplish diverse tasks and adapt to surroundings by morphing their shapes, such as jellyfish, octopus, and nudibranch. Looking at the enormous potential in engineering applications enabled by shape morphing, it is a major goal of soft robotics to imitate such ability. Thanks to the ever growing development of active materials, including liquid crystal elastomers (LCEs), hydrogels and shape memory polymers, progressive success has been achieved creating objects that evolve towards a predetermined target geometry through programmed trajectory. However, most proposed solutions either prohibit reprogrammability of the target geometry, face theoretical limitations on attainable geometry, lack mechanical stiffness, or forbid human intervention during actuation. Here we propose a robotic surface that allows large, reversible, reprogrammable, and controllable shape morphing into a variety of smooth 3D geometries. The robotic surface has a layered design with two active layers serving as artificial muscles, one passive layer serving as skeleton, and two layer of cover scales serving as artificial skin. The active layer is a grid of artificial muscle fibers made of heat responsive LCE embedded with stretchable heating coils, and the passive layer is a grid of polyimide ribbons glued to the active layers at selected bonding points. The heating coils are charged with electricity to apply local thermal stimulus such that both the magnitude and speed of the contraction of the LCE artificial muscle fibers can be manipulated. Then, owing to the special architecture of the robotic surface, the one-dimensional contraction of the artificial muscle fibers actuates both in-plane and out-of-plane local deformations that drive the entire surface morph into a variety of target 3D embeddings. Repeatable control schemes are derived upon understanding of this chain of effects via experiments, numerical simulations and theoretical analysis, which enables full control over the surface geometry as well as its morphing process, hence the name robotic surface. We further demonstrate that the proposed robotic surface provides sufficient mechanical stiffness and stability to interact with other objects, for example, it can move and manipulate objects placed on top of it, and lift up objects that are 6 times of its own weight. The proposed robotic surface offers functionalities suitable for a wide range of applications, such as shape display, human interaction and reconfigurable electronics. Yet, the fabrication remains relatively simple and accessible, which is a great advantage. We believe that this research shows promising novel approaches that may inspire further exploration by robotics and programmable matter researchers.