2013/04/17 by Wei Xiong, Jefferson Zhe Liu, Xiong, Wei +5
Engineering · Materials Science · Physics and Astronomy · #Advanced Sensor and Energy Harvesting Materials #Electrohydrodynamics and Fluid Dynamics #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Surface Modification and Superhydrophobicity #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1304.4770
Submitted to Physical Review E on September 17, 2012, manuscript ID: EW10844
arxiv created 2013/04/17 · openalex publication_date 2013/04/17 · arxiv updated 2013/04/18 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Reversible control of surface wettability has wide applications in lab-on-chip systems, tunable optical lenses, and microfluidic tools. Using a graphene sheet as a sample material and molecular dynamic (MD) simulations, we demonstrate that strain engineering can serve as an effective way to control the surface wettability. The contact angles θ of water droplets on a graphene vary from 72.5^∘ to 106^∘ under biaxial strains ranging from -10% to 10% that are applied on the graphene layer. For an intrinsic hydrophilic surface (at zero strain), the variation of θ upon the applied strains is more sensitive, i.e., from 0^∘ to 74.8^∘. Overall the cosines of the contact angles exhibit a linear relation with respect to the strains. In light of the inherent dependence of the contact angle on liquid-solid interfacial energy, we develop an analytic model to show the cos θ as a linear function of the adsorption energy Eads of a single water molecule over the substrate surface. This model agrees with our MD results very well. Together with the linear dependence of Eads on biaxial strains, we can thus understand the effect of strains on the surface wettability. Thanks to the ease of reversibly applying mechanical strains in micro/nano-electromechanical systems (MEMS/NEMS), we believe that strain engineering can be a promising means to achieve the reversibly control of surface wettability.