Another step toward autonomous robots patrolling remote areas. Imagine dropping off several million tiny self feeding robots in remote Afghanistan for instance to search for Osama Bin Laden? This is a far cry from that but hey it's a start.
The robot's energy source is the sugar in the polysaccharide called chitin that makes up a fly's exoskeleton. EcoBot II digests the flies in an array of eight microbial fuel cells (MFCs), which use bacteria from sewage to break down the sugars, releasing electrons that drive an electric current (see graphic).
In its present form, EcoBot II still has to be manually fed fistfuls of dead bluebottles, but the ultimate aim of the UWE robotics team is to make the droid predatory, using sewage as a bait to catch the flies.
"One of the great things about flies is that you can get them to come to you," says Melhuish. The team has yet to tackle this, but speculates that it would involve using a bottleneck-style flytrap with some form of pump to suck the flies into the digestion chambers.
With a top speed of 10 centimetres per hour, EcoBot II's roving prowess is still modest to say the least. "Every 12 minutes it gets enough energy to take a step forwards two centimetres and send a transmission back," says Melhuish.
But it does not need to catch too many flies to do so, says team member Ioannis Ieropoulos. In tests, EcoBot II travelled for five days on just eight fat flies - one in each MFC.