Robots inspired by termites assemble complex structures independently in a demonstration by researchers at the University of Cambridge. Researchers from the Wyss Institute and Harvard School of Engineering were also involved with the work, Justin Werfel is a co-author from Cambridge and explains that the machines work together by following a few simple environmental cues and traffic rules to build structures like castles and pyramids without seeing a plan and without any leadership. The robots use these cues and sensors that allow them to track where their contemporaries are to decide between taking another step up or laying down the brick they are carrying, resulting in bricks being placed in such a way that the next robot to come across that location will know whether to build higher or step onto that level themselves in order to start another level. This system of building stair cases that gradually become walls allow for the tiny machines to build structures much larger than themselves in only a matter of hours.
Although robots that work together are becoming more common recently, these robots inspired by termites assemble complex structures independently of each other, meaning that if some are lost the others will carry on without a hitch. In other systems the remaining robots would become confused and stall once their building scenario no longer matched their programmed behaviour. Like other robots before them, these are destined to work in conditions that are unsafe or unpleasant for humans and their independent nature makes them particularly suited to repairing structures in turbulent areas, such as levies or dams where flood waters have yet to recede. Should a handful of workers be lost, either to falling debris or rushing flood waters, those that remain will continue to work until the task is complete. On top of this, the number of robots used in a scenario can be scaled, allowing for small numbers for small jobs and large numbers for bigger ones. Although the little workers are quick to appraise their project and decide what should be done next, their small wheels don’t move them around very quickly.
The key to the abilities of these new robots is called swarm intelligence. Although each robot is small and can only carry out a small number of actions, together they are able to work towards a common goal, even if they do not know it individually. Each unit has just enough information to spot errors and correct them, but not enough to know what their siblings are doing, allowing these robots inspired by termites to assemble complex structures independently without worrying what their partners are up to. Four years of design resulted in these small robots, only 8 inches long and 4.5 inches wide, each equipped with 4 twisted triangle wheels powered by inexpensive motors and little arms to carry bricks. We probably won’t see these little workers laying out bricks in new sidewalks for another few years, but the groundwork is in place for a system that will allow humans to take a break from heavy lifting.
By Daniel O’Brien