A flow-rate-controlled double-nozzles approach for electrochemical additive manufacturing

The electrochemical additive manufacturing technique based on the meniscus-confined approach has been proved to be a powerful tool for fabricating nanoscale and microscale metal components. The stability of the meniscus is the key in this meniscus-confined approach to achieve high resolution and reliable product quality. In the present study, a double-nozzles design, which consists of a feed nozzle and a suction nozzle, is proposed for the meniscus confined electrochemical additive manufacturing technique. It was demonstrated that the proposed design possessed robust control of the stability of the meniscus by manipulating the feed and suction rates of the two nozzles in a quite large range. Various sizes of menisci can be easily obtained by utilising nozzles with different sizes. Compared with the pressure-controlled single-nozzle approach, the results showed that dense structures without dendrites can be fabricated by the double-nozzles design with larger current density due to the feed-and-suction process at the tip of the nozzles. The proposed flow-rate-controlled double-nozzles design was finally employed to fabricate some copper circuits and a Cu/CuNi thin film thermocouple to demonstrate its potential in fabricating electronic devices.基于弯液面约束法（meniscus-confined approach）的电化学增材制造（electrochemical additive manufacturing）技术，已被证实为制备纳米级与微米级金属构件的强有力工具。弯液面的稳定性是该弯液面约束法实现高分辨率与可靠产品质量的核心关键。本研究针对该弯液面约束电化学增材制造技术，提出了一种由进料喷嘴（feed nozzle）与抽吸喷嘴（suction nozzle）组成的双喷嘴设计（double-nozzles design）。研究证实，通过在较大范围内调节两个喷嘴的进料速率与抽吸速率，所提出的设计可对弯液面稳定性实现稳健调控。通过更换不同尺寸的喷嘴，可便捷获得不同规格的弯液面。相较于压力控制式单喷嘴方法，实验结果表明：得益于喷嘴尖端的进料-抽吸协同工艺，双喷嘴设计可在更高电流密度下制备出无枝晶的致密结构。本研究最终采用该流量调控型双喷嘴设计，制备了若干铜电路与一款铜/铜镍（Cu/CuNi）薄膜热电偶，以验证其在电子器件制备领域的应用潜力。