Impact of compound drops: a perspective

Drop interaction with solid surfaces upon impact has been attracting a growing community of researchers who are focusing more and more on 'complex' surfaces and 'complex' drops. Recently, we are observing an emerging research trend related to the investigation of compound drop impact. Compound drops consist of two or more distinct continuous phases sharing common interfaces, surrounded by a third phase. Examples are core-shell and Janus drops. In this review, we address the fundamental aspects of compound drop impact and discuss the current challenges related to experimental testing and numerical simulation of multiphase fluid systems. Furthermore, we provide a perspective on the technological relevance of understanding and controlling compound drop impact, ranging from 3D printing to liquid separation for water cleaning and oil remediation.

Automated summary

Researchers are increasingly focusing on the interaction of droplets with solid surfaces, paying more attention to 'complex' surfaces and droplets. A recent trend in research is the investigation of compound drop impact, which consists of two or more distinct continuous phases sharing common interfaces, surrounded by a third phase. This review addresses the fundamental aspects of compound drop impact and discusses challenges in experimental testing and numerical simulation of multiphase fluid systems.