TY - GEN
T1 - The capillary force between an AFM tip and a surface at different humidity
AU - Sheng, Chao Chen
AU - Lin, Jen-Fin
PY - 2008/12/1
Y1 - 2008/12/1
N2 - In the present study, the meniscus profiles of water bridges formed at different relative humidity are determined using the geometric relationships including the Kelvin equation and the force equilibrium formula established for the meniscus. The pull-off forces predicted by the present model show good agreement with the experimental results reported in the literatures. When the contact angles at two solid bodies are equal, the pull-off force is slightly elevated by an increase of the relative humidity of air, and is significantly elevated by an increase of the asperity radius. Furthermore, two hydrophobic surfaces with equally large contact angles lower the pull-off force. If a difference exists between the contact angles of two solid surfaces, the asperity with a hydrophilic surface incorporating with a smooth flat plate with a hydrophobic surface reduces the pull-off force.
AB - In the present study, the meniscus profiles of water bridges formed at different relative humidity are determined using the geometric relationships including the Kelvin equation and the force equilibrium formula established for the meniscus. The pull-off forces predicted by the present model show good agreement with the experimental results reported in the literatures. When the contact angles at two solid bodies are equal, the pull-off force is slightly elevated by an increase of the relative humidity of air, and is significantly elevated by an increase of the asperity radius. Furthermore, two hydrophobic surfaces with equally large contact angles lower the pull-off force. If a difference exists between the contact angles of two solid surfaces, the asperity with a hydrophilic surface incorporating with a smooth flat plate with a hydrophobic surface reduces the pull-off force.
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U2 - 10.1115/MicroNano2008-70204
DO - 10.1115/MicroNano2008-70204
M3 - Conference contribution
AN - SCOPUS:69949175646
SN - 0791842940
SN - 9780791842942
T3 - 2008 Proceedings of the ASME - 2nd International Conference on Integration and Commercialization of Micro and Nanosystems, MicroNano 2008
SP - 339
EP - 342
BT - 2008 Proceedings of the ASME - 2nd International Conference on Integration and Commercialization of Micro and Nanosystems, MicroNano 2008
T2 - 2008 ASME 2nd International Conference on Integration and Commercialization of Micro and Nanosystems, MicroNano 2008
Y2 - 3 June 2008 through 5 June 2008
ER -