Diagram (IMAGE) University of Exeter Caption This is a diagram showing 2 optically trapped rotors and how their motion can be used to control a free-floating cell (grey sphere). Credit Dave Phillips Usage Restrictions see credit 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.