Ferrofluid-infused slippery surface (IMAGE) City University of Hong Kong Caption Magnetic actuation of additive-free droplets on a ferrofluid-infused slippery surface. The actuation force is provided by the ferromagnetic wetting ridge that spontaneously forms around the deposited droplet. Credit Jianqiang Zhang et al./ DOI number: 10.1038/s41467-021-27503-1 Usage Restrictions Image must be used with appropriate caption and 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.