Assembly of the Hybrid Robot

Pneumatic System

For the initial testing of the soft robots, a compressed air tank system was used along with a pressure regulator to limit the internal pressure of an existing manifold. A series of three-way solenoid valves connected to the ports of the manifold would open and pressurize the channels, or close and restore the channels to atmospheric pressure.

The main problem encountered with this system was leakage at the channel interface. Inserting the tubes into the channels without adhesive was sufficient for early testing of the starfish and quadruped robots. Over time, this caused the interfaces to grow wider, letting air out of the robot and decreasing the maximum attainable curvature of the corresponding leg, and uniformity of pressurization. To solve this problem, we attempted to bind the tubes to the legs using first silicone, then ethyl cyanoacrylate (Krazy Glue). Only the cyanoacrylate closed the interfaces successfully. A pressure sensor (with digital readout) was added to assist with open-loop testing of the soft robots.

For final testing of the system and demonstration, the manifold and valves were mounted onto the youBot base plate, as pictured below.