Deepika Kurup, a 14-year-old high school student from Nashua, New Hampshire won a $25,000 prise from the 3M Young Scientist Challenge for her solar powered water purification system based on TiO2, ZnO nanoparticles, 3M Glass bubbles, and cement. The TiO2 and ZnO nanoparticles act as a photocatalyst to produce hydroxyl radicals that kills bacteria and the bubbles are used to reduce the weight of the purifier. Cement is a common local material in developing countries.