When you think of high school science projects, the inevitable volcano that puffs plumes of white smoke and spews forth a little make-believe lava probably comes to mind.Hamsa Sridhar of Kings Park High School in New York did not build the typical science project.She developed an inverted pair of optical tweezers with full motion control, demonstrated their ability to manipulate yeast cells in three directions (on X-Y-Z axes) and characterized the drag force in each direction. Sridhar selected the inverted configuration to balance radiation pressure with gravity.Her project so impressed a panel of judges that it won the top prize in the area of optics and photonics engineering. The $2500 award was presented by judges from SPIE at the Intel International Science and Engineering Fair in Albuquerque, N.M., in May. SPIE is one of more than 70 sponsors of the annual event, which attracted nearly 1500 students from 47 countries. Created in 1950, it is billed as the world’s largest precollege science fair.Three students from Hilton Head Preparatory School in South Carolina also were recognized by SPIE for their demonstration of how laser efficiency could be improved using rhodamine 6G in an Nd:YAG laser. The team, consisting of Chelsey L. Webb, Alexandra M. Smith and Ryan J. Clark, received a $1500 prize for their exhibit.Also recognized was Lauren R. Richey of Springville High School in Utah. Her project was on the structural properties of a 3-D biological photonic crystal. She was awarded $1000.