Durable Copper Nanowires for Flexible Curvature Sensors
: Broere, Linda; Gogoi, Rituporn; Barua, Amit; Mathews, Nidhin George; Granroth, Sari; Kolpakov, Kristofer; Mohanty, Gaurav; Peltola, Emilia; Sharma, Vipul
Publisher: Elsevier BV
: 2026
Chemical Engineering Journal Advances
: 101111
: 26
: 2666-8211
DOI: https://doi.org/10.1016/j.ceja.2026.101111
: https://doi.org/10.1016/j.ceja.2026.101111
: https://research.utu.fi/converis/portal/detail/Publication/515621127
Metal nanowire-based flexible conducting surfaces (FCS) are vital for next-generation flexible and wearable sensors. Copper nanowires (CuNWs) offer a low-cost alternative to the expensive silver nanowires for fabricating FCS, yet their poor stability remains a significant challenge. In this study, we report the synthesis of ultralong CuNWs using a hydrothermal polyol method across a range of temperatures (120 - 180°C). The CuNWs synthesised at 160°C (CuNW-160) demonstrated the best performance. CuNW-160 films maintained stable conductivity for over 60 days in ambient conditions and thermal stability up to 140°C. A capacitive curvature sensor was fabricated using FCS made with CuNW-160, which maintained consistent performance over 10,000 bending cycles and still showed good curvature sensitivity after 75 days. This highlights the potential use of the copper nanowires by tuning reaction temperature for use in reliable, low-cost flexible electronics.
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This work is supported by financial assistance from the project DURATRANS (364364, 2024–2027) under the framework of M-ERA.net. The authors are grateful to the Materials Research Infrastructure (MARI) at the University of Turku and Tampere Microscopy Center at Tampere University for providing infrastructural facilities. Rituporn Gogoi acknowledges SUSMAT for the research funding. We thank Ilari Angervo for assistance with X-ray diffraction measurements. We also thank Ermei Mäkilä for assistance in scanning electron microscopy, Markus Peurla for support in transmission electron microscopy and Shaharyar Siddique for support in sensor fabrication. Gaurav Mohanty and Nidhin George Mathews also acknowledge partial support from the project HERBIE (341050, 2021-2025) funded by Research Council of Finland.
