Abstract
We describe two new measurement techniques for studying the wetting behavior of a liquid on a surface. First, we measure the contact angle of a droplet, 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, we detect the current as a function of time, 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. Consequently, we can derive the radial velocity of the three-phase line of the droplet. The time resolution of the measurement technique is limited by the charging time of the initial capacitance, in our case approximately 0.5 ms. ©1999 American Institute of Physics.
Original language | English |
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Pages (from-to) | 3668-3673 |
Number of pages | 5 |
Journal | Review of Scientific Instruments |
Volume | 70 |
Issue number | 9 |
DOIs | |
Publication status | Published - 1999 |