2019/12/11 by Qiushi Zhang, Yunsong Pang, Zhang, Qiushi +11
Materials Science · Engineering · #Gold and Silver Nanoparticles Synthesis and Applications #Nanomaterials and Printing Technologies
paper · pdf · doi:10.48550/arxiv.2002.00704
Precise spatio-temporal control of surface bubble movement can benefit a wide\nrange of applications like high-throughput drug screening, combinatorial\nmaterial development, microfluidic logic, colloidal and molecular assembly,\netc. In this work, we demonstrate that surface bubbles on a solid surface are\ndirected by a laser to move at high speeds (> 1.8 mm/s), and we elucidate the\nmechanism to be the de-pinning of the three-phase contact line (TPCL) by rapid\nplasmonic heating of nanoparticles (NPs) deposited in-situ during bubble\nmovement. Based on our observations, we deduce a stick-slip mechanism based on\nasymmetric fore-aft plasmonic heating: local evaporation at the front TPCL due\nto plasmonic heating de-pins and extends the front TPCL, followed by the\nadvancement of the trailing TPCL to resume a spherical bubble shape to minimize\nsurface energy. The continuous TPCL drying during bubble movement also enables\nwell-defined contact line deposition of NP clusters along the moving path. Our\nfinding is beneficial to various microfluidics and pattern writing\napplications.\n