LOUISVILLE, Ky. 鈥 A branch of nanotechnology that showed great initial promise nearly 20 years ago could get a fresh look because researchers at the University of Louisville, Purdue University and Honda Research Institute USA Inc. have created a better 鈥渞ecipe鈥 for making microscopically tiny structures with more predictable, desirable properties 鈥 and potential for advances such as enhancing the efficiency of solar cells for energy use.