These Inflatable Pouch Motors Will Make Building Robots as Easy as Using Stickers

How easy is it to build a robot? Not very. How easy could it be to build a robot? Well, what if we try just sticking printable, inflatable actuators made of plastic onto origami (or anything else)? As Ryuma Niiyama and colleagues from the University of Tokyo and MIT have discovered, it really is that easy.

We covered these “pouch motors” (or “free-form planar soft actuators,” if you want to get technical) last August, in the context of robots with the potential to be entirely printable.

The actuators get printed on a custom-made fabrication machine that's nothing more than a 3-axis CNC holding a rod that can be heated, like a soldering iron. Moving the iron over two sheets of thermoplastic bonds them, leaving patterns of interlocking, inflatable pouches, and there’s your actuator. Hooking up a tube to the actuator with a syringe on one end allows the user to inflate and deflate the actuator, which will drag along anything that you’ve decided to stick it to.

To see how well this works in practice with people who have zero robotics experience, the researchers set up a user study:

Two 90-minutes animated origami workshops were held in a museum to study how children interact with sticky actuators. There were twenty participants at each workshop, all accompanied by their parents. The instructor demonstrated how to fold origami models and the use of sticky actuators. Then the participants were asked to make their own creations.

We observed that the combination of single-motion sticky actuators with a simple origami object could generate diverse behaviors and stories. [The figure on the right] shows animated origami objects from the workshop. As quoted from one participant, “The actuator was very interesting, and depending on the origami, there were different challenges”: the sticky actuator adds more challenges to the already complex art of folding origami. The actuation was even viewed as a new dimension to the origami art, as one participant mentioned: “I definitely enjoyed it. It added a new dimension to an art I love”.

We're also (somewhat selfishly) interested in how these pouch actuators might work in a home environment, especially if they’re scalable upwards a bit. Anyone with a 3D printer could construct a pouch motor in minutes to whatever specification they wanted: maybe you want to automatically open and close your pantry for your snack-fetching robot. Or maybe your laundry-folding robot needs some help with a stubborn sock drawer. The only potential issue is finding a source for the pressurized air needed to drive these things, but hey, there are always rockets.

[ Paper ]

Thanks Ryuma!