Contact angles and wetting velocity measured electrically

Abstract

Two new measurement techniques for studying the wetting behavior of a liquid on a surface are described. First, the contact angle of a droplet is measured by measuring the capacitance between a conducting droplet and a subsurface counter electrode. The estimated error in the measured contact angle is 2% for contact angles in the range between 60° and 120°. In the second measurement technique, the current as a function of time is detected, which provides information about the dynamics of a droplet wetting the substrate. The time-integrated current is related to the base area of the droplet.