science

Limbless organisms such as snakes can navigate nearly all terrain. In particular, desert-dwelling sidewinder rattlesnakes (Crotalus cerastes) operate effectively on inclined granular media (such as sand dunes) that induce failure in field-tested limbless robots through slipping and pitching. Our laboratory experiments reveal that as granular incline angle increases, sidewinder rattlesnakes increase the length of their body in contact with the sand. Implementing this strategy in a physical robot model of the snake enables the device to ascend sandy slopes close to the angle of maximum slope stability.

Think about that for a moment: a flashlight that shines for as long as you hold onto it. No more scrambling for and chucking away AA batteries. It could have an immediate impact on more than 1.2 billion people -- one-fifth of the world's population -- who, according to the World Bank, lack regular access to electricity.

Stunningly, no one on record has thought to use thermoelectric technology to power a flashlight. But for Ann, peltier tiles, which produce an electrical current when opposite sides are heated and cooled at the same time, were a convenient solution to a friend's study problem.