Durotaxis and antidurotaxis motion on gradient substrates*

By means of molecular dynamics simulation of a coarse-grained model, we explored the possibilities of causing the spontaneous motion of droplets onto brush and gel substrates with stiffness gradient, either in the direction of the gradient (durotaxis) or in the opposite direction (antidurotaxis). A detailed analysis of the driving force for durotaxis and antidurotaxis phenomena and an in-depth exploration of the relevant parameters are performed. We anticipate that our studies provide insights into the self-sustained motion of fluids onto gradient substrates with stiffness gradient and motivate further experimental research in this area.