Nanoparticle (IMAGE) University of Münster Caption Münster University – Wittkowski working group Credit A conical nanoparticle (gold-coloured) in water. The particle is exposed to an ultrasound wave (green arrows indicate the direction of wave propagation). Because the ultrasound impacts on the particle, a flow field is created in its surroundings (the black arrows in the background show the direction and strength of the flow at various positions). The flow field causes the propulsion of the particle in the direction of the red arrow. Usage Restrictions The use of the image is only permitted in connection with this press release and with reference to the source. License Original 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.