A Fundamental Study of Nano Electrodeposition Using a Combined Molecular Dynamics and Quantum Mechanical Electron Force Field Approach

Nano electrochemical additive manufacturing (Nano ECAM) is an emerging technology that combines the trends of miniaturization and additive manufacturing to fabricate complex 3D parts at the nano scale. A combined molecular dynamics and quantum mechanical electron force field approach is used in this work to study the electrochemical and physical input parameter effects on output deposition behavior to obtain fundamental understanding of Nano ECAM process. It was found that electron tunneling behavior occurs below a threshold interelectrode gap (IEG), which is not solvable by reducing the current. This tunneling would mean the electrons were not available to cause the electrolyte ions to deposit onto the substrate. Additionally, if the IEG was too high and the current was too low, the input electrons and cations from the electrolyte would combine and remain in a constant position near but not adsorbed to the surface. Furthermore, the effects of varying Watt's bath concentration were studied. It was found that there was an ideal concentration to perform Nano ECAM at, with values above and below causing deposition to occur less quickly and less efficiently. Finally, the work reported in this paper provides a very valuable computational framework for predicting the ECAM process results for subsequent experimental verification.