Soft Robotics: Shape Morphing and Locomotion by Controlled Buckling and 4D Printing


Conventional “hard” robots, constructed largely of metal or hard plastic elements, are widely used in manufacturing and can perform pre-programmed operations accurately and precisely, but often with limited adaptability and limited capability of handling fragile objects. By contrast, soft robots are primarily composed of soft, highly elastic materials and can deform continuously to achieve high adaptability. A unique feature of highly elastic elastomers is that they can undergo repeated buckling without much permanent deformation, which makes it possible to utilize buckling for robot locomotion. Buckling, a phenomenon of mechanical instability, is traditionally considered a mode of failure that results in a sudden and significant change in the shape of slender structures, e.g., beams, plates, and shells. However, a burgeoning trend, referred to as Buckliphilia, envisions mechanical instabilities as opportunities for new functionalities and applications. On the other hand, 4D printing, based on 3D printing, utilizes additional stimuli, such as heat, to transform the printed (simpler) structure into a new (more complex) one, reaching new design spaces unavailable to conventional methods. In this talk, I summarize some studies conducted in the Multiscale Systems Laboratory (MSL) at National Taiwan University on using controlled buckling and 4D printing for shape morphing and soft robots.