Wet Shape Memory Alloy Actuated Robotic Heart

This paper presents a conceptual design and preliminary analysis for a biomimetic robotic heart. The purpose of the robotic heart is to distribute hot and cold fluid to robotic muscles composed of wet shape-memory alloy (SMA) actuators. The robotic heart is itself powered by wet SMA actuators. A heart design concept is proposed and the feasibility of self-sustaining motion is investigated through simulation and experiment. The chosen design employs symmetric pumping chambers for hot and cold fluid. Analysis of this design concept shows that there exists a range of design parameters that will allow the heart to output more fluid than it uses. Additionally, it is shown that the heartbeat rate decreases as the system increases in size, and that the number of actuators and their length limit the power output of the pump. Experimental results from a prototype heart agree with the predicted trends from theoretical analysis and simulation.