Vibration-triggered spreading of nanofluid drops

This study explores the effects of nanoparticles on the dynamics of drop spreading under external vibration, presenting an advance in the understanding of nanofluid behavior on vibrating substrates. This work introduces insights into nanoparticle-mediated drop spreading, offering implications for improving particulate coatings, mini-mixers, and particle segregation technologies. By employing a twofold approach that combines oscillating drop dynamics with internal flow pattern analysis, we find how even small concentrations of hydrophilic or hydrophobized silica nanoparticles inside water sessile droplets significantly alter the spreading process on silanized glass surfaces. Our study allows distinct drop spreading regimes to be identified based on nanoparticle concentration and vibration amplitude, for both hydrophilic and hydrophobized nanoparticles. Through a comprehensive analysis, we demonstrate that the vibration-triggered spreading of nanofluids can lead to a stable and controlled manipulation of complex liquids.