Flexible 3D continuous GNSs/CNTs tube-network elastomer composites for high-performance EMI shielding and strain sensing

Abstract

While carbon-based nanocomposites are widely used for electromagnetic interference (EMI) shielding and flexible sensing, achieving uniform dispersion and structural continuity within flexible matrices remains challenging due to the intrinsic agglomeration of carbon nanomaterials. Furthermore, maintaining material flexibility in composites with 3\mathrm{D} continuous structures is difficult. In this study, we synthesized a carbon-based nanocomposite featuring a 3\mathrm{D} continuous network to fabricate flexible composite films. Morphological characterizations revealed a hollow, 3\mathrm{D} tube-network utilizing a graphite nanosheet framework, densely decorated with surface-grown carbon nanotubes. Upon infiltrating this network with flexible matrices, its microscopic and macroscopic structural integrity was exceptionally preserved. Consequently, the flexible film achieved a maximum EMI shielding effectiveness (SE) of 28.1 dB in the X-band, predominantly driven by absorption loss. Specifically, the composite utilizing a polydimethylsiloxane (PDMS) matrix exhibited optimal EMI SE while closely mirroring the stress-strain behavior of pure PDMS. Mechanical testing demonstrated an elongation at break of 51.9% and an ultimate tensile strength of 1.25 MPa. The composite film displayed extraordinary mechanical and piezoresistive stability, maintaining uncompromised performance after extensive stretch-release cycling and prolonged static strain. For human physiologic monitoring, the PDMS-based film successfully tracked articular movements—including the fingers, elbows, and cervical spine—accurately distinguishing subtle variations in joint flexion angles.

Graphical abstract

Keywords

carbon-based nanocomposites / $ 3\mathrm D $ continuous structure / electromagnetic shielding / strain sensing / wearable electronics

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