Evaporation investigation of nanofluid droplet affected by electrical field with periodically changed direction

The droplet evaporation phenomenon is very important for the development of droplet microfluidic technology. The existing studies have shown that high frequency and high electrical field strength have great effects on droplet evaporation and wetting characteristics respectively. However, the effects of high frequency together with high voltage on nanofluid droplet evaporation and wetting characteristics have not been studied and the mechanism is not clear. Therefore, the evaporation characteristics of nanofluid droplets at high voltage and high frequency were experimentally investigated to improve its evaporation rate and reveal its evaporation mechanism. The results show that the evaporation rates increase first and then decrease with the increase of voltage frequency (0–2 kHz), and the frequency at the high voltage obtained the maximum evaporation rate increases (90 Hz) when compared with the low voltage condition. Besides, the effect of electrical field on nanoparticles using the deposition surface was also explored, and the results show that the motion of the particles manipulated by the electrical field forces together with the oscillatory fluctuations of the droplets result in the enhancement of the evaporation rate of the nanofluid. [Display omitted] •Frequency obtained maximum evaporation rate increases when compared to low voltage.•Evaporation rate of nanofluids increases with improvement of concentration and voltage.•Oscillatory fluctuations combined nanoparticle motion result in evaporation enhancement.