Pneumatic actuators offer interesting perspectives in applications like soft robotics and interaction design. [Aidan Leitch] makes his own pneumatic actuators from silicone rubber. His actuators contain embedded air channels that can be filled with pressurized air and completely collapse to a flat sheet when no pressure is applied.
The process is based on the research work of Kevin C. Galloway et al. on “Zero Volume Air Chambers”. The team found that they could pour a thin layer of silicone rubber into a flat mold, then selectively apply a pattern of mold release to the surface of the cured layer using a laser-cut mask, and then pour a second layer of silicone on top. The mold release prevents the two layers of silicone from bonding together, leaving inflatable air channels behind that require close to zero volume when unpressurized.
To replicate their results, [Aidan’s] wrote an OpenSCAD script that generates 3D printable molds from black and white images. The molds include the mask for the release agent, whereas white regions in the image define the embedded air channels and black regions define solid silicone. Enjoy the video below where [Aidan] demonstrates his process!
Thanks to [Jean] for the tip!