Among the many things that humans cannot do (without some fairly substantial modification) is shifting our body morphology around on demand. It sounds a little extreme to be talking about things like self-amputation, and it is a little extreme, but it’s also not at all uncommon for other animals to do—lizards can disconnect their tails to escape a predator, for example. And it works in the other direction, too, with animals like ants adding to their morphology by connecting to each other to traverse gaps that a single ant couldn’t cross alone.
In a new paper, roboticists from The Faboratory at Yale University have given a soft robot the ability to detach and reattach pieces of itself, editing its body morphology when necessary. It’s a little freaky to watch, but it kind of makes me wish I could do the same thing.
These are fairly standard soft-bodied silicon robots that use asymmetrically stiff air chambers that inflate and deflate (using a tethered pump and valves) to generate a walking or crawling motion. What’s new here are the joints, which rely on a new material called a bicontinuous thermoplastic foam (BTF) to form a supportive structure for a sticky polymer that’s solid at room temperature but can be easily melted.
The BTF acts like a sponge to prevent the polymer from running out all over the place when it melts, and means that you can pull two BTF surfaces apart by melting the joint, and stick them together again by reversing the procedure. The process takes about 10 minutes and the resulting joint is quite strong. It’s also good for a couple hundred dettach/reattach cycles before degrading. It even stands up to dirt and water reasonably well.
Hellbound and Down 