This article reports a synthesis that yields 4.4 g of Cu nanowires in 1 h, and a method to coat 22 g of Cu nanowires with Ag within 1 h. Due to the large diameters of Cu nanowires (≈240 nm) produced by this synthesis, a Ag:Cu mol ratio of 0.04 is sufficient to coat the nanowires with ≈3 nm of Ag, and thereby protect them from oxidation. This multigram Cu‐Ag core–shell nanowire production process enabled the production of the first nanowire‐based conductive polymer composite filament for 3D printing. The 3D printing filament has a resistivity of 0.002 Ω cm, >100 times more conductive than commercially available graphene‐based 3D printing filaments. The conductivity of composites containing 5 vol% of 50‐µm‐long Cu‐Ag nanowires is greater than composites containing 22 vol% of 20‐µm‐long Ag nanowires or 10‐µm‐long flakes, indicating that high‐aspect ratio Cu‐Ag nanowires enable the production of highly conductive composites at relatively low volume fractions. The highly conductive filament can support current densities between 2.5 and 4.5 × 105A m−2depending on the surface‐to‐volume ratio of the printed trace, and was used to 3D print a conductive coil for wireless power transfer.
Three-dimensional (3D) electrically conductive micro/nanostructures are now a key component in a broad range of research and industry fields. In this work, a novel method is developed to realize metallic 3D micro/nanostructures with silver-thiol-acrylate composites via two-photon polymerization followed by femtosecond laser nanojoining. Complex 3D micro/nanoscale conductive structures have been successfully fabricated with ∼200 nm resolution. The loading of silver nanowires (AgNWs) and joining of junctions successfully enhance the electrical conductivity of the composites from insulating to 92.9 S m−1at room temperature. Moreover, for the first time, a reversible switching to a higher conductivity is observed, up to ∼105S m−1at 523 K. The temperature-dependent conductivity of the composite is analyzed following the variable range hopping and thermal activation models. The nanomaterial assembly and joining method demonstrated in this study pave a way towards a wide range of device applications, including 3D electronics, sensors, memristors, micro/nanoelectromechanical systems, and biomedical devices, etc.
more » « less- NSF-PAR ID:
- 10308337
- Publisher / Repository:
- IOP Publishing
- Date Published:
- Journal Name:
- International Journal of Extreme Manufacturing
- Volume:
- 1
- Issue:
- 2
- ISSN:
- 2631-8644
- Page Range / eLocation ID:
- Article No. 025001
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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