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Updated: Oct 19, 2025

Impacts of Free-falling Spheres on a Deep Liquid Pool with Altered Fluid and Impactor Surface Conditions
Published on: February 17, 2019
Spatio-temporal maneuvering of impacting drops
Xing Han1,2, Xin Tang1,2, Haibo Zhao1,2,3
1Department of Mechanical Engineering, The University of Hong Kong, Hong Kong. lqwang@hku.hk.
Abstract:
Controlling impacting drops on nonwetting surfaces is desired in multifarious processes. Efforts have been made to solely spatially control the drop movement after the impact or solely temporally reduce liquid-solid contact via surface design. We present a fin-stripe nonwetting surface that enables spatial offset maximization and temporal contact minimization simultaneously, just via structure design without the need for external energies. The wetting stripe provides a large wettability gradient for lateral movement, while the macroscale nonwetting fin restricts the drop movement direction and confines drop spreading for contact time reduction. The fin-stripe surface can decrease the contact time by roughly 30% and provide a normalized lateral distance of roughly 20, an order of magnitude larger than the reported values. Our surface enables effective spatio-temporal maneuvering of impacting drops, essential for various applications that involve liquid transport.
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