An electric field can suppress the Leidenfrost state by electrostatically attracting liquid to the surface, which results in significantly higher heat transfer. This study highlights and quantifies the statistical nature of wetting during electrostatic suppression via electrical impedance characterization of Leidenfrost pools. Firstly, electrical impedance characterization is used to study the onset of suppression of the Leidenfrost state. Two different threshold voltages are defined and measured. The first threshold voltage corresponds to the onset of transient (intermittent) wetting and the second threshold corresponds to the onset of continuous wetting. The effect of the temperature and the applied AC waveform frequency on the threshold voltages is studied. Next, the wetted area is measured for different temperatures and voltages. The statistical nature of wetting during electrostatic suppression of the Leidenfrost state is characterized. The measured wetting enhancement indicates that heat transfer can be enhanced by an order of magnitude via electrostatic suppression. Together, these results provide an in-depth understanding of electrostatic suppression, and highlight electrical impedance measurements as a powerful diagnostic tool for this field.

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