Pneumatics are a common way to add some motion to soft robotic actuators, but adding it to a robot can be somewhat of a chore. A method demonstrated by [Jackson K. Wilt] et al. (press release, preprint) involves using a 3D printing to extrude two materials: one elastomeric material and a fugitive ink that is used to create pneumatic channels which are dissolved after printing, leaving the empty channels to be filled with air.
By printing these materials with a rational, multi-material (RM-3DP) custom nozzle it’s possible to create various channel patterns, controlling the effect of compressed air on the elastomeric material. This way structures like hinges and muscles can be created, which can then be combined into more complex designs. One demonstrated design involves a human-like hand with digits that can move and grasp, for example.
In the demonstration the elastomeric material is photopolymerizable polyurethane-acrylate resin, with the fugitive ink being 30 wt% Pluronic F-127 in water. The desired pattern is determined beforehand with a simulation, followed by the printing and UV curing of the elastomeric resin.
As is typical of soft robotics implementations, the resulting robots are more about a soft touch than a lot of force, but could make for interesting artificial muscle designs due to how customizable the printing process is.
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