A Novel Flexible Bio-Inspired Pneumatic Valve Adapter for Soft Robotic Vasculature

Abstract

This paper proposes a novel flexible pneumatic valve adapter that seeks inspiration from vascular systems found in nature. Evolved vascular systems, such as the human cardiovascular system, pump fluid through a complex system composed of a single reservoir/pump. These systems regulate flow by systematically closing and opening valves appropriately through soft biological material constriction. The proposed pneumatic valve emulates this with two concentric flexible tubes with a single hole on the inner tube and patterned holes on the outer tube. This allows it to decrease the quantity of tubes and valves required for pneumatically actuated soft robots, with the trade-off being increased motion of the valve spool (the inner tube). Previous versions of this adapter used rigid members which decreased the number of tubes tethering the robot to a pressure source, but also hindered the soft robotic nature and movement. This adapter utilizes flexible materials to minimize the valve’s effect on the robot’s range of motion. The tubes have holes that are patterned by custom design determined by the needs of the soft robot with which it is to be used. The inner tube can be moved rotationally or translationally within the outer tube to align with designated holes to pressurize and depressurize chambers in a soft robot with only a single lightweight valve.