Polypyrrole-coated copper nanowire-threaded silver nanoflowers for wearable strain sensors with high sensing performance

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2021-08, Vol.417, p.127966, Article 127966
• Main Authors: Zhao, Songfang, Meng, Xiangying, Liu, Lin, Bo, Wenjie, Xia, Meili, Zhang, Ruliang, Cao, Duxia, Ahn, Jong-Hyun
• Format: Article
• Language: English
• Subjects: Cu@PPy NW–threaded Ag NFs; Fracture sensing mechanism; Sensing range; Strain sensor
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.127966

[Display omitted] •Core-shell copper-polypyrrole nanowires with tunable properties are achieved.•Cluster structure of Cu@PPy threaded Ag NFs is assembled.•Cluster structure endows the sensor with large stretchability and high sensitivity.•Diverse sensing mechanisms are proposed to explain the superiority. Although the development of wearable strain sensors with a wide sensing range (>50%) and high sensitivity (gauge factor (GF), > 100) is highly desirable, it also presents a grand challenge owing to the inverse relationship between sensitivity and sensing range in designing strain-sensing materials and geometric structures. In this study, we fabricate versatile conductive composites by embedding polypyrrole-coated copper nanowire (Cu@PPy NW)–threaded Ag nanoflowers (NFs) in a poly(styrene-block-butadiene-block-styrene) (SBS) matrix. The fabrication process is simple, energy–saving, and scalable. Moreover, the obtained cluster structures derived from Cu@PPy NW–threaded Ag NFs endow the composites with excellent electromechanical performance, which is demonstrated by its wide sensing range (up to 185% strain), high sensitivity (GF up to 1.28 × 106), as well as excellent reliability and stability. The superiority in sensing range and sensitivity is a result of the combination of the fracture–sensing mechanism, constrained crack–propagation mechanism by the matrix, slippage–sensing mechanism, and double bridge functions of Ag NFs and Cu@PPy NWs. The high performance allows the strain sensors to monitor full–range human motions.