Materials and Methods for Biodegradable Soft Robotic Systems

In our striving to secure a livable world for all, soft robotic systems may offer unique solutions to complex problems. Among the grand challenges in the field are the development of high-performance green materials, end-of-lifetime considerations in complex (soft) systems, and their energy efficiency. This talk discusses bioderived materials and sustainable fabrication methods for soft robotic systems that biodegrade, yet are of high performance and resilience. We discuss recent advances in 3D printing of soft biogels for proprio-and exteroceptive actuators. Next steps include the printing of complex soft systems where a multitude of different components need to work together symbiotically. Here, we present a multi-material printing system that combines gelatin-based hydrogels with a new biodegradable support material. This organic ink maintains up to 60 ° overhang and is printable over gaps to structurally supports the main biogel body, while triggered dissolution enables its selective removal and the formation of internal cavities. Therefore, the creation of vascular networks, tunable scaffolds and embedded sensors within a single printing process becomes feasible. Beyond pneumatic and vaccum-based actuation mechanisms, we introduce a systematically-determined compatible materials systems for the creation of fully biodegradable, high-performance electrohydraulic soft actuators. We elucidate their fundamental operating principles and provide materials combinations that enable power-efficient electrohydraulic actuators void of detrimental interfacial charging. Finally, concepts for powering energy-autonomous soft aquatic robots and aerial drones are introduced.