Title Discrete Cellular Soft Robotics

Soft robots offer adaptability and resilience for manipulation and control through a balance between compliance and stiffness, with continuous deformations in contrast to rigid mechanical systems. Despite these benefits, soft robots have faced inherent challenges associated with their use of soft materials, including limits on the loads that they can support, issues with their scalability, difficulties in integrating heterogeneous system properties, a requirement for production tooling, and the need to actively maintain static configurations. We present a novel method to construct cellular soft robots that can address these constraints by discretely assembling mechanical metamaterials. By combining two simple regular part types (rigid and compliant) we show that we can design high-performance anisotropic structures. Combining these with distributed actuation results in actively deformable robotic systems. We demonstrate the utility of this approach in a novel application as a continuously deformable cellular hydrodynamic soft robot based on bio-inspired swimming motions. We describe the design, fabrication, control, and testing of this 1.5m snake-like robot in a tow tank and show that traveling wave kinematics can be used to generate thrust while maintaining low drag through the continuous deformation of the cellular structure. Simulations reveal beneficial control over vortex generation and shedding, a phenomenon also shown in nature with efficient swimming patterns in fish. We conclude by projecting the performance of this scalable construction system to enable new regimes of soft robotic systems not possible with current traditional methods.