Temperature-regulated directional bounce of impacting droplets on gradient grooves

The gradient grooved surfaces were fabricated using the standard photolithography technique on a silicon wafer. Then, the movement direction of impacting droplets on gradient grooved structures can be regulated by changing the substrate temperature. The impinging droplet rebounds towards the denser microgrooved region at contact boiling state, while towards to the sparser region at Leidenfrost film boiling state.172