Planning to build a host of robot minions, but don’t have time to plug them in when their battery goes low? Well, then you need to enable them to feed themselves by finding their own power, and Brian Mayton might have just the solution for you. His electric field sensing robot, featured above, uses a series of electromagnetic sensors to hone into the 60 Hz signal produced by an electric outlet, and then plug itself it. This is a neat approach because it is actually detecting the thing that it wants (power), rather than relying on a computer vision system to find something that looks like an outlet.
It should come as no surprise that there is a long history of robot designs to accomplish this task. If you want to learn more, Hizook has an excellent write-up of the history of self-feeding robots. [Thanks, Travis!]