It turns out that robots don't need to be BigDog-sized to be freaky. Scientists at the University of Illinois have created one a mere centimeter (half-inch) in size built on a 3D-printed hydrogel backbone. The "ew" part is what powers it: a strip of skeletal muscle cells triggered by an electric current. Previous biobots built with heart tissue couldn't be controlled, but muscle cells can be activated with electric pulses and made to "walk" at different speeds by varying the frequency. If that's not making you queasy yet, how about this: the researchers think that such devices could be used for surgical robots, mobile environment detectors and even "programmable tissue engineering." That sounds like a noble goal, but we imagine Cyberdyne Systems thought the same thing.