Soft pneumatic actuators by digital light processing combined with injection-assisted post-curing

The soft robotics displays huge advantages over their rigid counterparts when interacting with living organisms and fragile objects. As one of the most efficient actuators toward soft robotics, the soft pneumatic actuator (SPA) can produce large, complex responses with utilizing pressure as the only input source. In this work, a new approach that combines digital light processing (DLP) and injection-assisted post-curing is proposed to create SPAs that can realize different functionalities. To enable this, we develop a new class of photo-cross linked elastomers with tunable mechanical properties, good stretchability, and rapid curing speed. By carefully designing the geometry of the cavities embedded in the actuators, the resulting actuators can realize contracting, expanding, flapping, and twisting motions. In addition, we successfully fabricate a soft self-sensing bending actuator by injecting conductive liquids into the three-dimensional (3D) printed actuator, demonstrating that the present method has the potential to be used to manufacture intelligent soft robotic systems.