A heartbeat for soft robots

Softness, compliance, is omnipresent in nature and is essential for many of its remarkable qualities. Soft robotics is an emerging research field that aims to make robots safer and smarter by using compliant materials and structures, inspired by nature. This PhD thesis is part of the EU-funded project `Hybrid Heart’, in which a consortium of partners aims to develop a total artificial heart (TAH) based on soft robotics technology. We explore if it is possible to drive the future soft TAH by making use of autonomous oscillations, thereby minimizing the need for rigid or electronic components. With that goal, we develop a soft hysteretic valve that passively transforms a continuous fluid flow into timed pulses.

Using this remarkably simple system, we develop a more widely applicable control concept for fluid-driven soft robots. Crucially, this new concept enables soft robots to exhibit desired behavior in interaction with their environment, without the need for electronics or external control inputs. We demonstrate a soft four-legged robot that can change its behavior in response to physical cues, as well as a driving system for a soft total artificial heart, as we set out to do. As such, the work presented in this thesis is a step towards more autonomous soft robots in general, and specifically towards the development of a fully implantable and bio-compatible heart prosthesis that might one day provide a much-needed solution for millions of end-stage heart failure patients.