Insects don’t have the capacity to reason, and yet some are capable of building complex structures and executing complex foraging expeditions with no central organizing. That’s why researchers recently sent ants to the International Space Station and will observe how the change in gravity affects the ants’ ability to organize.
At Harvard, scientists are taking their inspiration from termites, which can spend generations building mounds that stretch multiple feet into the air. On Thursday, a research team revealed a crew of iPad-sized robots that can build structures with no input from a central leader.
“The key inspiration we took from termites is the idea that you can do something really complicated as a group, without a supervisor, and secondly that you can do it without everybody discussing explicitly what’s going on, but just by modifying the environment,” principal investigator Radhika Nagpal said in a release.
Known as TERMES, the robots currently can build any kind of structure with uniform foam bricks. Someday, they could be used to place sandbags before a flood or build habitats on other planets.
Each robot works independently. It knows what the finished product should look like, but it doesn’t know what its fellow robots are planning to do. Instead, it looks at the current state of the object it is working on and algorithms work out where it should add the next brick. The robots are constantly reevaluating what needs to happen next, so if a brick falls or one robot places a brick in the area another robot had been working on, that robot can readjust. The system works with one or 50 robots–it doesn’t matter.
“We co-designed robots and bricks in an effort to make the system as minimalist and reliable as possible,” paper co-author Kirstin Petersen said in the release. “Not only does this help to make the system more robust, it also greatly simplifies the amount of computing required of the onboard processor. The idea is not just to reduce the number of small-scale errors, but more so to detect and correct them before they propagate into errors that can be fatal to the entire system.”
The robots work with the help of just four sensors, which keeps their cost down. They are also capable of climbing the height of one brick, which means they can use the bricks as stairs to build very tall structures.
The team, which is made up of researchers from the Harvard School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering, spent four years developing the robots. They presented their work today in Science (subscription required) and at the annual AAAS conference in Chicago. They previously developed Kilobots, a low-cost swarm of robots that work together much like TERMES.