Jhou, Jhe-WeiJhe-WeiJhouHONG-REN JIANG2025-11-202025-11-202025-09-101744683Xhttps://www.scopus.com/record/display.uri?eid=2-s2.0-105015633755&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/733886Carbon nanotubes (CNTs), typically magnetically inert, can be effectively aligned in polydimethylsiloxane (PDMS) using moderate magnetic fields when hybridized with Fe3O4 nanoparticles. We demonstrate that these CNT-Fe3O4 hybrids rapidly self-organize into aligned, bundled structures under an applied magnetic field (∼120 mT), driven by local magnetic gradients originating from Fe3O4 nanoparticles interacting with trace magnetic impurities within the CNTs. This field-induced anisotropy yields composites with significantly enhanced electrical conductivity, lower percolation thresholds, and superior piezoresistive sensitivity compared to non-aligned samples. Furthermore, we observe evidence of spontaneous local organization improving conductivity even without an external field. This simple, functionalization-free hybridization strategy offers a powerful route to control microstructure in soft composites, enabling tunable electromechanical properties for applications like soft sensors and providing insights into magnetically assisted self-assembly in hybrid materials.falsejournal article10.1039/d5sm00449g2-s2.0-105015633755