From the description for Super-Releaser Robotics‘s recent soft robot Glaucus:
We’ve been developing methods for creating durable, inexpensive soft body robots. Fundamentally, the technology involves designing a robot in CAD, 3d printing molds for the interior and exterior of the bot, and casting it in silicone.
These methods offer a few advantages over traditional subtractive fabrication. First, iteration is fast and dynamic. It is simple to design a parametric bot in CAD and simultaneously print multiple experiments and prototypes to flesh out and understand new forms.
Second, casting is inexpensive and incredibly repeatable. Once a successful design is fleshed out, creating an army of exact duplicates of this winning robot is as simple as casting the mold multiple times. The mold can even be duplicated for mass casting. This means stress testing never risks destroying one precious irreplaceable prototype.
Third, the designs that are developed using these methods easily translate into a manufacturing context. Printing and machining high volume production molds based on the initial CAD follows the same tool chain as any other industrial casting process. If a project calls for thousands of identical silicone robots, HTV (high temperature vulcanizing) silicones can be injected into machined molds just like any mass produced plastic part….
Featured Learning System Tutorial!
Soft Quadruped Robot: 3d print your way to a walking quadruped with no hard moving parts. This robot may sound complex – a silicone robot with intertwining interior chambers that walks using air pressure – but the process to make it is relatively simple. Even though it’s got a lot of stuff going on all you really have to learn is how to mix and pour silicone and you’re well on your way to having your very own quadrupedal soft robot. (read more)