This project from the Self-organizing Systems Research (SSR) Group at Harvard is an exploration of how a robot can adapt and change it’s environment dynamically. It’s also really cute, in it’s own way.
It starts by randomly tossing toothpicks, and then moves on to casting foam, which works in a similar way (the still-liquid foam runs down a bit before solidifying) –ramp created, the robot makes it’s way up to the summit.
More from IEEE Spectrum:
Researchers from Harvard University and Worcester Polytechnic Institute have taken inspiration from animals like weaver birds, termites, and beavers, and developed robots capable of using cheap materials to build large structures. Let’s start with the beavers, ‘cause they’re the cutest. Beavers (and weaver birds) build things by sticking together large amounts of, uh, sticks. This new robot can do something very similar with prefabricated sticks (toothpicks) and glue. At this point, the robot in question has a deposition mechanism with which it just “flings” individual toothpicks (a technical term, apparently) after adding glue to them. While it has approximately zero control over placing the toothpicks into any sort of arrangement that would make structural sense, the sheer number of toothpicks plus a generous helping of glue means that eventually, the bot can build ramps or anything else that on some level consists of a random pile of wood and glue.
Termites, on the other hand, build structures out of mud, without any underlying framework. Robots can do something similar with urethane casting foam. By successively depositing layers of liquid that puff up as they dry, a robot can build ramps or any anything else that on some level consists of of a random blob of foam. Yes, there’s a theme here, and it’s not a sophisticated one, but part of the point is that it doesn’t have to be sophisticated: with cheap materials and patient robots, you can make structures that are perfectly functional, even if they’re not particularly efficient (or pretty).
I’m curious to know if the glue on the toothpicks is necessary, though. Given a large enough supply of toothpicks, they would eventually find an angle of repose against the box and form a ramp. Their unique shape means they would kind of ‘lock’ together. This is a much more effective method in some ways, since it means the robot only needs to have a general idea of it’s environment to adapt. Of course, the chances of a landslide (pick-slide?) happening increase, and with or without glue, random throwing means you cannot optimize the number of toothpicks you can carry around — so it’s a versatility vs. weight/resources game.