MAXIMUM PRESSURE CAUSED BY DROPLET IMPACT IS DEPENDENT ON THE DROPLET SIZE

Understanding how pressure on the contact area of a droplet impacting on a solid surface changes is important to reveal the mechanism of droplet impact. Particularly, how the maximum value of the pressure depends on the impact velocity and the size of the droplet is an important topic of interest in the study of droplet impact. In this study we show that the maximum pressure p(max) on the contact area of a droplet impacting on a rigid substrate increases with droplet size. Using an array of MEMS-based force sensors, we were able to directly measure p(max), which occurred at the very beginning stage of the impact. We also confirmed the dependence of impact induced pressure on the droplet size by measuring the critical impact velocity that causes the liquid penetration through a mesh for droplets with different sizes. The finding in this study is useful for modeling the maximum pressure caused by droplet impact.