Rectification of Mobile Leidenfrost Droplets by Planar Ratchets. Issue 9 (24th June 2019)

• Record Type: Journal Article
• Authors: Li, Jing; Zhou, Xiaofeng; Zhang, Yujie; Hao, Chonglei; Zhao, Fuwang; Li, Minfei; Tang, Hui; Ye, Wenjing; Wang, Zuankai
• Is Part Of: Small. Volume 16:Issue 9(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-06-24
• Subjects: collective coordination -- fluidic devices -- individual effect -- Leidenfrost droplets -- rectification; Nanotechnology -- Periodicals; Nanoparticles -- Periodicals; Microtechnology -- Periodicals; 620.5
• DOI: 10.1002/smll.201901751
• Languages: English
• ISSNs: 1613-6810

Abstract

Abstract: The self‐transportation of mobile Leidenfrost droplets with well‐defined direction and velocity on millimetric ratchets is one of the most representative and spectacular phenomena in droplet dynamics. Despite extensive progress in the ability to control the spatiotemporal propagation of droplets, it remains elusive how the individual ratchet units, as well as the interactions within their arrays, are translated into the collective droplet dynamics. Here, simple planar ratchets characterized by uniform height normal to the surface are designed. It is revealed that on planar ratchets, the transport dynamics of Leidenfrost droplets is dependent not only on individual units, but also on the elegant coordination within their arrays dictated by their topography. The design of planar ratchets enriches the fundamental understanding of how the surface topography is translated into dynamic and collective droplet transport behaviors, and also imparts higher applicability in microelectromechanical system based fluidic devices. Abstract : 2D planar ratchets are developed to enable the rectification of Leidenfrost droplets. Distinct from classic millimetric ratchets where the Leidenfrost droplet moves along the asymmetric ratchet, droplets on planar ratchets rely on both the individual features and their collective arrangements. This results in the varying droplet mobility ranging from 10 cm s −1 along the descending slope to −7 cm s −1 against the descending slope.