Vibration induced droplet generation on textured surfaces

We report a new method to create droplets from a large drop by using surface texture and vibration. Drops are vibrated on a PDMS substrate textured with ring shaped mesa structures. The vibrating contact line is modeled as a parametric oscillator. Droplets are created under the effect of pinning of the contact line, Laplace pressure difference on the mesa and inside the well and the spring force pulling the contact line back during vibration. We created droplets of 0.1-0.3 muL from a 0.5 mL drop by vibrating the drop at its third mode shape. Droplets are generated at the frequency of contact line oscillation of the drop.