Shape memory composite fiber actuators have been extensively studied due to their excellent flexibility, weavability, actuation performance, and low-cost continuous fabrication. However, integrating both high actuation strain and high actuation stress within a single fiber-based material system remains a key challenge. In this study, we developed a high-performance shape memory composite fiber using a scalable wet-spinning process. The fiber exhibited 15 MPa actuation stress and up to 76% actuation strain within 1 s during thermal shrinkage, along with a high work capacity of 1339 J kg^-1. The electrical actuation achieved through efficient Joule heating also demonstrated 13 MPa actuation stress. Mechanistic analysis revealed excellent interfacial bonding between carbon nanotubes (CNTs) and the polymer (polyurethane) matrix. Furthermore, the combined effect of CNTs and crystalline regions promoted tensile alignment of polymer chains, leading to improved mechanical and actuation properties of the fiber. This study demonstrated that the fiber structure enabled integrated actuation and programmed deformation in various 2D/3D configurations, with promising applications in future intelligent soft robotics, wearable devices, and smart textiles.

Alignment, functionalization and detection of carbon nanotube (CNT) bundles are vital processes for utilizing this one-dimensional nanomaterial in electronics. Here, we report a polymer-assisted wet shearing method to acquire super-aligned crater-patterned CNT arrays by nanobubble (NB) self-assembly with a "migrate and aggregation" mechanism and use craters to controllably mold even-sized nanodisks periodically along CNT bundles with tunable densities. This green, low-cost method can be extended to diverse substrates and fabricate different nanodisks. As an example, the Ag-nanodisk-patterned CNT arrays are utilized as substrates of surface-enhanced Raman scattering (SERS) for rhodamine 6G (R6G) and methylene blue (MB) in which a linear correlation is found between the SERS intensity and the CNT bundle density due to the periodic distribution of hot spots, enabling a spectral detection of CNT bundles and their densities by conventional dye molecules. Distinguishing from routine morphological characterization, this spectral method possesses an enhanced accuracy and a detection range of 0.1–2 μm^–1, showing its uniqueness in the detection of CNT bundle density since the intensity of traditional spectral merely relates to the quantity of CNTs, exhibiting its potential in future CNT-bundle-based electronics.

The demand for lightweight, thin electromagnetic interference (EMI) shielding film materials with high shielding effectiveness (SE), excellent mechanical properties, and stability in complex environments is particularly pronounced in the realm of flexible and portable electronic products. Here, we developed an ultra-thin film (CNT@GC) in which the glassy carbon (GC) layer wrapped around and welded carbon nanotubes (CNTs) to form a core–shell network structure, leading to exceptional tensile strength (327.2 MPa) and electrical conductivity (2.87 × 10⁵ S·m⁻¹). The CNT@GC film achieved EMI SE of 60 dB at a thickness of 2 μm after post-acid treatment and high specific SE of 3.49 × 10⁵ dB·cm²·g⁻¹, with comprehensive properties surpassing those of the majority of previous shielding materials. Additionally, the CNT@GC film exhibited Joule heating capability, reaching a surface temperature of 135 °C at 3 V with a fast thermal response of about 0.5 s, enabling anti-icing/de-icing functionality. This work presented a methodology for constructing a robust CNT@GC film with high EMI shielding performance and exceptional Joule heating capability, demonstrating immense potential in wearable devices, defense, and aerospace applications.