SoftER: A Spiral Soft Robotic Ejector for Sorting Applications

For over thirty years optical belt drive configura- tions are being used in food industries to automatically sort produce in high operating speeds. Despite their benefits, these multi-component assemblies are prone to faults, difficult to clean, and require frequent maintenance that halts the production lines for considerable amount of time. In this paper, we adopt the abundantly occurring spiral motions encountered in nature and translate them to the proof-of-concept design and development of a soft pneumatic actuator (SPA), the SoftER. This novel actuator has the ability to rapidly unwind when pressurized to deliver impact forces. We explore this inherently low-cost and simple design and its potential to replace current systems based on the results of an application case study presented in this paper. Simulation driven optimization methods are leveraged, utilizing quasi-static and dynamic finite element methods models, to create a scalable framework for selecting the best performing design parameters for each application. Using rapid manufacturing processes the optimized actuator is constructed and physical testing validates its high-speed and impact force delivering capabilities.