One-dimensional noble metal nanostructures are important components in modern nanoscience and nanotechnology due to their unique optical, electrical, mechanical, and thermal properties. However, their cost and scalability may become a major bottleneck for real-world applications. Copper, being an earth-abundant metallic element, is an ideal candidate for commercial applications. It is critical to develop technologies to produce 1D copper nanostructures with high monodispersity, stability and oxygen-resistance for future low-cost nano-enabled materials and devices. This article covers comprehensively the current progress in 1D copper nanostructures, most predominantly nanorods and nanowires. First, various synthetic methodologies developed so far to generate 1D copper nanostructures are thoroughly described; the methodologies are in conjunction with the discussion of microscopic, spectrophotometric, crystallographic and morphological characterizations. Next, striking electrical, optical, mechanical and thermal properties of 1D copper nanostructures are highlighted. Additionally, the emerging applications of 1D copper nanostructures in flexible electronics, transparent electrodes, low cost solar cells, field emission devices are covered, amongst others. Finally, there is a brief discussion of the remaining challenges and opportunities.

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Efficient heat dissipation is a critical requirement for sustained performance and failure prevention of microelectronic components. Thermal interface materials are used to fill the voids at the solid interface between the device and the heat sink to create a thermally conducting pathway for heat dissipation. This work reports flexible elastomer composite embedded copper nanowires with high aspect ratios (2500–5000), leading to a thermal percolation network at very low volume filler loading fractions of ≈0.009Φ. In order to achieve a high thermal conductivity at ultralow filler fractions, the copper nanowires are freeze‐casted into a monolithic sponge, to create an interconnected network. The composites formed by subsequently embedding the nanowire sponge in elastomer matrix exhibit a thermal conductivity of 3.1 ± 0.2 W mK−1, a 19‐fold enhancement over the pristine matrix, in a temperature range between 20 and 80 °C. The effect of thermal contact resistance at nanowire junctions is substantially reduced by in situ microwave welding of the nanowires. The use of Ecoflex, an ultrasoft silicone elastomer as the matrix, along with very low filler loadings of copper nanowire networks, keeps the elastic modulus <250 kPa, retaining the high compliance of the composites.

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