Stamp-sized device to disinfect water created
Researchers at Stanford University have built a stamp-sized device to disinfect contaminated water within minutes when kept out in the sun. The tiny device harnesses the visible portion of sunlight's spectrum, which contains about 50% of total energy. In a sample of 25 ml with a bacterial concentration of 1,000,000 per ml, the device killed 99.99% germs within 20 minutes.