Molecular dynamics study of direct localized overpotential deposition for nanoscale electrochemical additive manufacturing process
Molecular dynamics study of direct localized overpotential deposition for nanoscale electrochemical additive manufacturing process
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DOI：
10.1016/j.precisioneng.2019.01.010
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发表时间：
2019-03
期刊：
影响因子：
--
通讯作者：
A. Brant;M. Sundaram
中科院分区：
文献类型：
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作者：
A. Brant;M. Sundaram
采用准确定性分子动力学模拟方法研究了离子在恒电位电极作用下的迁移和沉积过程。被改变的输入参数包括工具尺寸、工具电位、衬底电位、电极间间隙和浓度。监测的存款的输出参数包括随时间的沉积高度、随时间沉积的原子数、平均电流密度和沉积质量。电极间间隙或浓度的变化导致沉积速率和质量的变化，这些变化彼此成反比。发现存在最佳半径以同时最大化沉积速度和质量。工具和衬底之间的电压差的增加提高了沉积的速率和总体质量，但是电极之间的最高电压差由于离子耗尽而导致存款中心的中空区域。低浓度类似地导致离子耗尽条件。由于小工具或低浓度导致的少量阳极-阳离子相互作用导致存款吞没工具，这是由于较少的总静电相互作用将阳离子排斥出工具。发现增加的输出电流密度不一定与增加的输出存款质量一致。
A quasi-deterministic molecular dynamics simulation was performed to study the migration and deposition of ions under the influence of charged, constant-potential electrodes. The input parameters that were varied include tool size, tool potential, substrate potential, interelectrode gap, and concentration. The output parameters of the deposit that were monitored included deposition height over time, number of atoms deposited over time, averaged current density, and deposition quality. Variation of the interelectrode gap or concentration resulted in changes to the deposition rate and quality that were inversely related to each other. It was found that there is an optimal radius to simultaneously maximize deposition speed and quality. An increase in the voltage difference between the tool and substrate improved the rate and overall quality of the deposition, but the highest voltage differences between the electrodes led to a hollow region in the center of the deposit due to ion depletion. Low concentration similarly led to ion depletion conditions. A low amount of anode-cation interactions due to a small tool or low concentration resulted in a deposit that engulfed the tool due to less overall electrostatic interactions repelling the cations from the tool. It was found that an increased output current density did not necessarily coincide with increased output deposit quality.