Modeling and analysis of soft robotic surfaces actuated by pneumatic network bending actuators

Soft robots are a nascent field that aims to provide a safe interaction with humans and better adaptability to unstructured environments. Many tentacle-like one-dimensional soft robots that can mimic the basic motion in nature are developed owing to ease of design and fabrication. To expand the spectrum of soft robots, this paper gives a detailed introduction of a new type of sheet-like two-dimensional soft robot. This soft robot is called soft robotic surface (SRS), which is actuated by pneumatic network bending actuators. An analytical model of the SRS is constructed based on the minimum potential energy method, which considers both its geometry complexity and material nonlinearity. The comparisons among the analytical, experimental, and numerical results demonstrate that the analytical model can accurately predict the SRS deformation. The maximum root mean squared error for the surface morphing is 3.429 mm, which is less than 5% of the maximum displacement for the free end. The effects of the actuating pressure and structural parameter on the SRS deformation are also investigated. The results reveal that the deformation shape of the SRS can be reconfigured by controlling the applied pressure. And the bending angle of the two actuators both decreases with the increase of the width and thickness of the soft surface. The SRS extends the research on soft robots and the developed analytical model also solves the fundamental problem of how to programme the surface morphing of soft robot surfaces. Finally, we fabricate a soft gripper that can grasp object objects with different sizes, shapes, and stiffness, which demonstrates the application of the SRS.