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Graphene-based coaxial hybrid fibers (CHFs) with a typical core–sheath structure have attracted extensive attention in recent years because of their potentially excellent mechanical performance. However, direct introduction of the micrometer-thick graphene stack structure on the extremely inert fiber surface with little negative effect has barely been reported so far and is still a great challenge. In the present work, a facile and cost-efficient dimensionally confined hydrothermal reduction, static adsorption, and thermal-assisted shrinkage sequential treatment strategy was developed to fabricate one-dimensional CHFs. The large-scale reduced graphene oxide–metal organic framework (RGO–UIO-66) hybrid layer and poly­(p-phenylene benzobisoxazole) (PBO) fiber serve as the sheath part and core part, respectively, and the final product is denoted as PGU–CHFs. The experimental results confirmed that the prepared monofilament composite with thermoplastic polyurethane (PGU–CHF–TPU) exhibited an excellent and stable intrinsically self-healing efficiency (about 85%) over 5 cycles and an extraordinary uvioresistant performance (increased by 128%) compared to those of pristine PBO fibers after 288 h UV aging irradiation. Moreover, the anti-ultraviolet (UV) properties of PGU–CHFs at 96 h are basically at the optimum level among most of the reported literatures at present after comparison. The highly near-infrared photothermal conversion ability and stability of micrometer-thick RGO stack structure and the synergism of RGO–UIO-66 hybrid sheath layer including UV adsorption, shielding attenuation, and reflection are responsible for the satisfactorily interfacial self-healing efficiency and UV-resistance properties of PGU–CHFs, respectively. Considering the diversities and versatilities of RGO and MOFs, the proposed fabrication strategy will promisingly endow PBO fibers with great application potential in the other fields such as fiber-based sensors and smart fibers.

Wide bandgap (WBG) semiconductors have attracted significant research interest for the development of a broad range of flexible electronic applications, including wearable sensors, soft logical circuits, and long‐term implanted neuromodulators. Conventionally, these materials are grown on standard silicon substrates, and then transferred onto soft polymers using mechanical stamping processes. This technique can retain the excellent electrical properties of wide bandgap materials after transfer and enables flexibility; however, most devices are constrained by 2D configurations that exhibit limited mechanical stretchability and morphologies compared with 3D biological systems. Herein, a stamping‐free micromachining process is presented to realize, for the first time, 3D flexible and stretchable wide bandgap electronics. The approach applies photolithography on both sides of free‐standing nanomembranes, which enables the formation of flexible architectures directly on standard silicon wafers to tailor the optical transparency and mechanical properties of the material. Subsequent detachment of the flexible devices from the support substrate and controlled mechanical buckling transforms the 2D precursors of wide band gap semiconductors into complex 3D mesoscale structures. The ability to fabricate wide band gap materials with 3D architectures that offer device‐level stretchability combined with their multi‐modal sensing capability will greatly facilitate the establishment of advanced 3D bio‐electronics interfaces.

In high-performance flexible and stretchable electronic devices, conventional inorganic semiconductors made of rigid and brittle materials typically need to be configured into geometrically deformable formats and integrated with elastomeric substrates, which leads to challenges in scaling down device dimensions and complexities in device fabrication and integration. Here we report the extraordinary mechanical properties of the newly discovered inorganic double helical semiconductor tin indium phosphate. This spiral-shape double helical crystal shows the lowest Young’s modulus (13.6 GPa) among all known stable inorganic materials. The large elastic (>27%) and plastic (>60%) bending strains are also observed and attributed to the easy slippage between neighboring double helices that are coupled through van der Waals interactions, leading to the high flexibility and deformability among known semiconducting materials. The results advance the fundamental understanding of the unique polymer-like mechanical properties and lay the foundation for their potential applications in flexible electronics and nanomechanics disciplines.

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