title: Tailoring percolating conductive networks of natural rubber composites for flexible strain sensors via a cellulose nanocrystal templated assembly.
abstract: Conductive polymer composites (CPCs) just above the percolation threshold exhibit a unique strain-reversible electric response upon application of tensile strain, which can be used to prepare strain sensors. However, it is difficult to balance the electric conductivity which is fundamental to a stable output signal and the strain sensing sensitivity due to the relatively dense conductive pathways of the traditional CPCs. Constructing a "brittle" but effective conductive network structure in CPCs is the essential foundation of a desirable sensing material. Here, we demonstrate for the first time that highly flexible, stretchable, sensitive, and reversible strain sensors can be fabricated by a facile latex assembly approach, in which nontoxic, sustainable and biodegradable cellulose nanocrystals played a key role in tailoring the percolating network of conductive natural rubber (NR)/carbon nanotube (CNT) composites. The resulting nanocomposites with a continuous 3D conductive structure exhibited a very low electrical conductivity percolation threshold (4-fold lower than that of the conventional NR/CNT composites), high resistivity and sensitivity (gauge factor ≈ 43.5) and meanwhile good reproducibility of up to 100% strain. The proposed materials and principles in this study open up a novel practical approach to design high performance flexible sensors for a broad range of multifunctional applications.
authors.affiliation: State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China. xxzwwh@scu.edu.cn canhuilu@scu.edu.cn.
authors.forename: Shuman
authors.initials: S
authors.lastname: Wang
authors.forename: Xinxing
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wu
authors.forename: Canhui
authors.initials: C
authors.lastname: Lu
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D004553:Electric Conductivity; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000648:ultrastructure; D012408:Rubber / Q000737:chemistry*; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D037742:Nanotubes, Carbon; D002482:Cellulose; D012408:Rubber