Deicing of Sessile Droplets Using Surface Acoustic Waves

Abstract

Deicing has significant relevance in various applications such as transportation, energy production, and telecommunication. The use of surface acoustic waves (SAWs) is an attractive option for deicing as it offers several advantages such as localized heating, in situ control, low power, and system integration for highly efficient deicing. Here, we report an understanding of the dynamics of deicing of microlitre volume water droplets (1 to 30 μL) exposed to low power (0.3 W) SAW actuation using an interdigitated electrode on a piezoelectric (LiNbO 3 ) substrate. We study the time variation of the volume of liquid water from the onset of SAW actuation to complete deicing, which takes 2.5 to 35 s depending on the droplet volume. The deicing phenomenon is attributed to acoustothermal heating which is found to be greatly influenced by the loss of ice adhesion with the substrate and the acoustic streaming within the liquid water. Acoustothermal heating inside the droplet is characterized by the temperature distribution inside the droplet using infrared thermography, and acoustic streaming is observed using dye-based optical microscopy. A rapid enhancement in deicing is observed upon the detachment of ice from the substrate and the onset of acoustic streaming, marked by a sudden increase in the liquid water volume, droplet temperature, and heat transfer coefficient. The deicing time is found to increase linearly with droplet volume as observed from experiments and further verified using a theoretical model. Our study provides an improved understanding of the recently introduced SAW-based deicing technique that may open up the avenue for a suitable alternative to standard deicing protocols.

Harnessing a Vibroacoustic Mode for Enabling Smart Functions on Surface Acoustic Wave Devices ‐ Application to Icing Monitoring and Deicing

“…As we estimated, the electrical driving costs-which are important for autonomous operating or mobile devices-can be lower than those in electrothermal heating. [32] The method and results presented in the manuscript were based on earlier findings on energy-efficient deicing with surface acoustic waves, [14,15,31,32] and ice-sensing with shear thickness waves. [21] We believe this and similar application cases are straightforwardly scalable, and cost-efficient, as they add systemstate tracking (temperature and mechanical loads) with minimal additional peripheral components (only a power switch relay).…”

“…for liquid nebulization or, as it has been recently demonstrated, for surface deicing. [12][13][14][15] In actuation applications, resonance peaks can be several hundred kHz to a few MHz in width, providing reproducible and stable activation conditions. Those setups can also be used in sensing applications, for example in delay line configurations [16] or at large wavelengths.…”

A Review of Icing Research and Development of Icing Mitigation Techniques for Fixed-Wing UAVs

“…The sketch of the SAW-induced melting process of glace ice aggregates is shown in Figure 12 Zeng et al [147] experimentally demonstrated that SAWs can reduce ice adhesion. Nampoothiri et al [148] deiced microliter-sized droplets with low-power SAW actuation using interdigitated electrodes on a piezoelectric (LiNbO3) substrate, suggesting the future development of efficient SAW-based deicing systems. Jacob et al [146] demonstrated that energy-efficient deicing and prevention of ice formation could be achieved for larger volume piezoelectric substrates using high-frequency thickness-shear acoustic vibrations, with reduced ice adhesion.…”