Video: Carbon-based paper folds itself up, walks away

Researchers around the globe have developed a variety of sheetlike polymers and gels capable of folding in response to changes in temperature, pH, or other stimuli. Now, a team in China reports today in Science Advances that it has designed a carbon-based paper that takes the next step forward, literally. In this case, the sheet is made from an ultrathin carbon-based material called graphene oxide that folds, walks, and even turns corners on its own (as seen in the video above). Selected areas of the paper contract when heated with infrared light and swell back up again when the light is turned off. That allows the researchers to make paper strips that walk forward, backward, and turn when prompted by bursts of laser light. Down the road, such materials could prove valuable for making sensors able to detect humidity, light, and electric fields, as well as insectlike robots capable of carrying far more than their body weight.