Raw data of Fig. 4A from Cu/Carbon nanotube composites: research trends and outlook

We present research progress made in developing copper/carbon nanotube composites (Cu/CNT) to fulfil a growing demand for lighter copper-substitutes with superior electrical, thermal and mechanical performances. Lighter alternatives to heavy copper electrical and data wiring are needed in automobiles and aircrafts to enhance fuel efficiencies. In electronics, better interconnects and thermal management components than copper with higher current- and heat-stabilities are required to enable device miniaturization with increased functionality. Our literature survey encouragingly indicates that Cu/CNT performances (electrical, thermal and mechanical) reported so far rival that of Cu, proving the material's viability as a Cu-alternative. We identify two grand-challenges to be solved for Cu/CNT to replace copper in real-life applications. The first grand-challenge is to fabricate Cu/CNT with overall performances exceeding that of copper. To address this challenge, we propose research directions to fabricate Cu/CNT closer to ideal composites theoretically predicted to surpass Cu performances (i.e. <i>those containing uniformly distributed Cu and individual aligned CNTs with beneficial CNT–Cu interactions</i>). The second grand-challenge is to industrialize and transfer Cu/CNT from lab-bench to real-life use. Toward this, we identify and propose strategies to address market-dependent issues for niche/mainstream applications. The current best Cu/CNT performances already qualify for application in niche electronic device markets as high-end interconnects. However, mainstream Cu/CNT application as copper-replacements in conventional electronics and in electrical/data wires are long-term goals, needing inexpensive mass-production by methods aligned with existing industrial practices. Mainstream electronics require cheap CNT template-making and electrodeposition procedures, while data/electrical cables require manufacture protocols based on co-electrodeposition or melt-processing. We note (with examples) that initiatives devoted to Cu/CNT manufacturing for both types of mainstream applications are underway. With sustained research on Cu/CNT and accelerating its real-life application, we expect the successful evolution of highly functional, efficient, and sustainable next-generation electrical and electronics systems.

本研究阐述了铜/碳纳米管复合材料（copper/carbon nanotube composites，Cu/CNT）的研发进展，旨在满足日益增长的轻量化铜替代材料需求，这类材料需具备优异的电学、热学与力学性能。为提升燃油效率，汽车与航空领域亟需替代重型铜质电气及数据布线的轻量化材料。在电子领域，为实现器件小型化并提升功能集成度，亟需性能优于铜、具备更高电流与热稳定性的互连结构及热管理组件。本研究的文献调研结果令人鼓舞，目前已报道的Cu/CNT复合材料的电学、热学与力学性能已可与铜相媲美，证实了该材料作为铜替代材料的可行性。
本研究明确了Cu/CNT复合材料在实际应用中替代铜所需攻克的两大核心挑战。第一大挑战为制备综合性能优于铜的Cu/CNT复合材料。针对该挑战，本研究提出了研发方向，即制备更接近理论预测可超越铜性能的理想复合材料的Cu/CNT，这类理想复合材料需满足铜基体均匀分散、碳纳米管（carbon nanotube，CNT）单独排列且碳纳米管与铜基体间存在有益界面相互作用的条件。第二大挑战为实现Cu/CNT复合材料的工业化量产，将其从实验室阶段推向实际应用。为此，本研究明确并提出了针对细分/主流应用场景的市场适配性问题解决方案。
目前最优的Cu/CNT复合材料性能已可满足高端互连应用的细分电子设备市场需求。但将Cu/CNT作为铜替代材料应用于传统电子器件及电气/数据布线的主流场景，仍为长期目标，需依托符合现有工业规范的工艺实现低成本大规模量产。主流电子器件应用需实现低成本的碳纳米管模板制备与电沉积（electrodeposition）工艺，而数据/电力电缆则需采用基于共电沉积（co-electrodeposition）或熔融加工的制造方案。本研究注意到（结合实例），针对上述两类主流应用场景的Cu/CNT复合材料制造相关研发项目已在推进中。随着Cu/CNT复合材料研究的持续深入及实际应用的加速落地，我们期待高性能、高效率且可持续的下一代电气与电子系统能够得以成功研发并应用。