Drop impact on rigid substrate with controlled motion

We report a method to reduce the contact time of a droplet impacting on a solid substrate by controlling the substrate motion. This motion is sinusoidal and triggered by a detection of the moment of impact using a MEMS-based force sensor fabricated on the substrate. We show that substrate motion can reduce the contact time by ~50% for a flat superhydrophobic surface. The most efficient reduction of the contact time was reached when moving the substrate with a period similar to the spreading time of the droplet. Especially, combining substrate textures and its motion could lead to a reduction of approximately 80% of the contact time.