Neutrophil Avoids Microparticles (IMAGE) Yale University Caption Yale engineers created microparticles that mimic bacteria and can be manipulated with holographic optical tweezers. The ones pictured here emit a repulsive chemical “scent,” which the approaching neutrophil cell tries to avoid as it squeezes past. Credit Eric Dufresne and Holger Kress/Yale University Usage Restrictions Image may be used with appropriate credit given. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.