Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan.
J Colloid Interface Sci. 2012 Apr 15;372(1):170-5. doi: 10.1016/j.jcis.2012.01.038. Epub 2012 Jan 28.
Two-dimensional dip-pen nanolithography (DPN) combined with laser-assisted heating is studied using molecular dynamics (MDs) simulations. The effects of humidity, deposition temperature, heating rate (laser-assisted patterning), and cooling rate on ink molecules are evaluated in terms of molecular transference, alkanethiol meniscus characteristics, surface binding energy, number of transferred chains, pattern characteristics, and the diffusion coefficient of ink molecules. The simulation results clearly show that the number of molecules transferred significantly increases with increasing humidity, which leads to increases in meniscus size and pattern size. The surface binding energy decreases and the diffusion coefficient of ink molecules increases with increasing humidity and deposition temperature. The dwell stage has the largest number of molecules transferred and the largest diffusion distance of ink molecules. The number of vaporous water molecules increases when the temperature is above 300 K, which limits meniscus growth and leads to unstable deposition. The DPN transfer efficiency can be significantly enhanced by increasing the laser pulse energy/heating rate. The transfer efficiency improves as the system humidity increases to saturation (374 water molecules).
采用分子动力学（MDs）模拟研究了二维蘸笔纳米光刻（DPN）与激光辅助加热相结合的技术。从分子迁移、烷硫醇弯月面特性、表面结合能、转移链数量、图案特征和墨水分子扩散系数等方面评估了湿度、沉积温度、加热速率（激光辅助图案化）和冷却速率对墨水分子的影响。模拟结果清楚地表明，随着湿度的增加，转移的分子数量显著增加，这导致弯月面尺寸和图案尺寸增大。表面结合能随着湿度和沉积温度的增加而降低，墨水分子的扩散系数增加。停留阶段转移的分子数量最多，墨水分子的扩散距离最大。当温度高于 300 K 时，水蒸气分子的数量增加，这限制了弯月面的生长，导致沉积不稳定。通过增加激光脉冲能量/加热速率，可以显著提高 DPN 的转移效率。随着系统湿度增加到饱和（374 个水分子），转移效率提高。
