Abstract
It is known that a droplet is held on the vertically vibrating pool of the same kind of liquid. When the frequency of oscillation is at the resonance of the apparatus, the droplet is found to a certain position on the pool regardless of the initial dropped position. In this case, the lifetime of a droplet is as long as several hours, perhaps because of the larger amplitude of vibration acceleration than the gravity as previously reported. Then we investigated waveform at the resonance frequency to clarify the relationship with the position where the droplet is retained. The amplitude, phase, and average displacement of the surface of oscillating pool were measured by a laser displacement meter and FFT analyzer. The average displacement is relevant to the position of a droplet, while the amplitude and phase are not; in the distribution where the regression plane of the average displacement is subtract, its minimum position is almost the same as the retained droplet.
