Welcome to the amazing world of soft substrates. These materials are made of silicon gels and have the same texture as panna cotta—but without the delicious flavor. They are used in a range of applications, especially in the pharmaceutical industry, because their biocompatible and antiadhesive properties make them resistant to corrosion and bacterial contamination. These substrates are so soft that they can be deformed (reversibly) by the capillary forces that occur at the edges of droplets when placed on their surfaces. However, droplets move very slowly on these surfaces; in order to flow, the droplets have to dynamically deform the substrates and overcome the resistance created by the substrate's viscoelastic proprieties. A millimeter-sized droplet placed on a substrate positioned vertically will flow at a speed of only between a few hundred nanometers per second and a few dozen micrometers per second. In other words, it would take the droplet three hours to move just one meter! This slowing effect is known as viscoelastic braking and is a big obstacle to the more widespread use of soft substrates, especially in manufacturing.