'Photo album' shows dances of droplets

The splash from rain hitting a windowpane or printer ink hitting paper all comes down to tiny droplets hitting a surface, and what each of those droplets does. Cornell researchers have produced a high-resolution "photo album" of more than 30 shapes an oscillated drop of water can take. The results, a fundamental insight into how droplets behave, could have applications in everything from inkjet printing to microfluidics. Susan Daniel, assistant professor of chemical and biomolecular engineering, led the study, published in Physical Review E, Aug. First author Chun-Ti Chang, a Cornell graduate student, designed and performed the experiments, which involved a high-speed, high-resolution camera. Paul Steen, professor of chemical and biomolecular engineering, and his former student, Josh Bostwick, led the theoretical portion of the study. "What is really special about this study is the high-quality imaging we were able to capture of these oscillating droplets," Daniel said.