A partnership between MIT and the India Institute of Technology has produced a new solar-powered autoclave for sterilising medical equipment in developing nations, where access to electricity is limited. Autoclaves use steam to kill bacteria. For this, water needs to be heated either electrically or by burning fuel, which may be scarce in impoverished regions. The new solar-powered autoclave incorporates a tank that releases water into a set of pipes. The pipes are attached to a copper plate with a heat-absorbing black coating on its upper surface. That surface is also layered with transparent silica-based aerogel, which allows sunlight to pass through. Polished aluminium mirrors on either side of the plate also help to concentrate the sunlight and when the plate gets hot, the liquid water in the pipes turns to steam and reaches the autoclave.