Self-sustained droplet motion on gradient substrates

Gradient substrates can cause the motion of droplets without providing an external energy source. Here, various substrate designs will be presented, which are studied by means of extensive molecular dynamics simulations, with motion taking place in the direction of the gradient, as well as in the opposite direction. The influence of various system parameters for each system will be presented and the underlying mechanisms will be explained, anticipating that this will provide valuable information for relevant experimental designs.