Localized electrochemical deposition (LECD) is a promising and economical three-dimensional (3D) microstructure fabrication method. As the current research on LECD mainly focuses on the deposition of copper and nickel, this work investigated the fabrication of silver microcolumns via LECD, using polyethyleneimine (PEI) as an additive. Firstly, the effects of PEI on the surface morphologies and structures of the deposited microcolumns were studied; it was found that adding PEI to the electrolyte could reduce the column surface roughness and promote the formation of uniform and straight columnar structures. Thereafter, the effects of the deposition voltage and initial electrode spacing on the LECD process performance were studied using a 0.08- g/L PEI electrolyte; nanoindentation was performed to determine the hardness and Young's modulus of the silver microcolumns. Furthermore, based on the experimental results, a possible action mechanism for PEI and the formation mechanism of the microcolumns' nodular structures were proposed. This technology was used to manufacture high-density and high-quality interconnects and electrodes for electrochemical biosensors.

局部电化学沉积 (LECD) 是一种有前途且经济的三维 (3D) 微结构制造方法。由于目前对 LECD 的研究主要集中在铜和镍的沉积上，这项工作研究了通过 LECD 制造银微柱，使用聚乙烯亚胺 (PEI) 作为添加剂。首先，研究了PEI对沉积微柱表面形貌和结构的影响；发现在电解液中加入PEI可以降低柱表面粗糙度，促进均匀直柱状结构的形成。此后，使用 0.08-g/L PEI 电解液研究沉积电压和初始电极间距对 LECD 工艺性能的影响；进行纳米压痕以确定硬度和杨氏 s 银微柱的模量。此外，基于实验结果，提出了PEI可能的作用机制和微柱结节结构的形成机制。该技术用于制造用于电化学生物传感器的高密度和高质量互连件和电极。