With an additional light source, they could control where Neusbot swims and cleans. Powered only by the sun, the robot would simply move forward. They controlled Neusbot's direction by changing the angle of its light source. Li and UCR chemistry professor Yadong Yin specialize in making robots from nanomaterials. 'I'm confident about their stability in high salt situations,' Li said. Additionally, the nanomaterials can withstand high salt concentrations without damage. Neusbot's bottom layer is hydrophobic, so even if an ocean wave overpowered the film, it would float back to the surface. The nanorods convert light energy into heat, vaporizing the water and powering pulsed motion across the water's surface. The middle layer of the film is porous, holding water as well as iron oxide and copper nanorods. It is a similar principle that powers Neusbot, except with light as the power source. The steam from boiling water powered the motion of early trains. We solved the problem with a tri-layer film that behaves like a steam engine,' Li explained. 'There aren't many methods to achieve this controllable movement using light. Technical details of this achievement are described in a new Science Robotics paper. This type of motion is key to controlling the robot and getting it to function where and when you want. While other scientists have created films that bend in response to light, they have not been able to generate the adjustable, mechanical oscillation of which Neusbot is capable. These insects traverse the surface of lakes and slow-moving streams with a pulsing motion, much like scientists have been able to achieve with the Neusbot, which can move on any body of water.

Researchers dubbed the film Neusbot after neustons, a category of animals that includes water striders.

If sunlight is used for power, this machine is sustainable, and won't require additional energy sources,' said UCR chemist Zhiwei Li. 'Our motivation was to make soft robots sustainable and able to adapt on their own to changes in the environment. Powered by light and fueled by water, the film could be deployed indefinitely to clean remote areas where recharging by other means would prove difficult.

Robot 2.0 hd movie view