Elastocapillary wake

Partially wetting droplets naturally deform soft substrates by the action of surface tension. These deformations are usually localized to a narrow region near the contact line, forming a so-called 'Elastocapillary ridge'. Here, we show that substrate deformations delocalize when droplets slide along the surface above a certain velocity. In particular, we observe a pair of parallel ridges that slowly fade away behind the droplet. To characterize this elastocapillary wake, we perform interferometry to measure the shape of the deformed substrate in space and time. We quantify the formation and relaxation of the elastocapillary wake as a function of sliding speed.