A revolutionary new solar energy technology that turns water into steam without boiling the entire container of water has become the basis for new devices to sanitize medical and dental instruments and human waste in developing countries, scientists said here today.
Prototypes of the devices, which need no electricity or fuel, were the topic of one of the keynote addresses at the opening of the 246th National Meeting & Exposition of the American Chemical Society (ACS), the world's largest scientific society. The meeting, which features almost 7,000 reports on new advances in science and other topics, continues through Thursday in the Indiana Convention Center and downtown hotels.
Naomi Halas, D.Sc., pointed out that almost 2 billion people live in areas of the world without a regular supply of electricity. That electricity is key to using machines called autoclaves, which produce scorching-hot steam to sterilize medical and dental instruments. Without that basic machine, doctors must rely on chemicals, which can be costly and difficult to transport, to prevent the spread of germs and disease from medical and dental instruments.
"We have developed a solution, our solar steam technology," Halas said. She is with Rice University. "It is completely off-grid, uses sunlight as the energy source, is not that large, kills disease-causing microbes effectively and relatively quickly and is easy to operate. This is an incredibly promising technology."
Halas and colleagues have prototypes of two solar steam machines. One is the autoclave for sterilizing medical and dental instruments. The second is an autoclave for disinfecting human and animal wastes, which are another major source of disease transmission in developing countries and other resource-limited areas. The technology could be expanded to provide steam for direct use in purifying dirty or salty water for drinking and cooking — with the solar-generated steam simply allowed to condense into pure distilled water. Possibilities also exist for adapting the technology to produce steam to spin small electric turbines to generate electricity.