Resonant properties of sessile droplets; contact angle dependence of the resonant frequency and width in glycerol/water mixtures

Mechanical vibrations of pendant liquid droplets

“…However, this effect is only present when the drop profile is shallow and does not appear to be significant for large contact angles [19].…”

“…Previous studies have considered the effects of viscous damping on droplet motion [1,19]. Sources of damping include viscous dissipation effects in the liquid, which may be enhanced by the presence of a substrate, or as a result of the presence of surface contamination layers.…”

“…In contrast, there have been numerous studies that provide models that attempt to describe the vibrational response of sessile drops [19,[21][22][23][24][25][26]. Perhaps the most simple and intuitive of these models was derived by Noblin et al [23] Noblin's approach considers the surface of the drop as a bath of liquid of finite depth, h, on which standing capillary waves can occur.…”

“…A key part of this work involves extending the studies of Noblin et al [23] and Sharp et al [19,24,25] and to include experimental studies and a discussion of how damping effects influence the vibrational properties of pendant liquid drops with sizes smaller than the capillary length of the liquids being studied. on the surface of a silicon photodiode which was attached to a home built amplifier circuit and connected to a computer using a National Instruments USB-6008 data acquisition card.…”

“…However, there are additional considerations when interpreting the vibrational properties of sessile and pendant drops. For example, the presence of a substrate can have a significant influence on the damping of the droplet motion and on the permissible vibrational modes [19].…”