SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4426-y
Biomedical Mg alloys are candidate biodegradable metals for orthopedic and cardiovascular implants, yet their in vivo service life is governed by coupled mechanical-chemical attack that accelerates loss of mechanical integrity. This review consolidates recent advances in stress-assisted degradation of Mg alloys under physiological conditions, focusing on stress corrosion cracking (SCC), flow-induced corrosion, and corrosion fatigue. Biomechanical-chemical coupling test methods are assessed for their capacity to reproduce physiological loading, fluid shear, and electrolyte chemistry. Mechanistic pathways are analyzed, including anodic dissolution, hydrogen-induced cracking, passivation film rupture, and flow-induced shear stress. Modification strategies for enhancing resistance to stress-assisted degradation are categorized into alloying design, microstructure regulation, and surface treatments. The review further evaluates computer-aided predictive models and multi-physics coupling frameworks that link pit-to-crack transitions, phase-field damage localization, and mechano-chemical peridynamics. Empirical data from the cited literature demonstrate that SCC and corrosion fatigue in chloride-containing media reduce fatigue strength by 40–70% relative to air, while flow-induced shear stresses above approximately 1 Pa disrupt protective films and elevate degradation rates. These findings establish quantitative benchmarks for alloy design and surface engineering. The review concludes that integrating multi-physics modeling with physiologically relevant testing is essential for predicting implant service stability and accelerating clinical translation of high-performance biomedical Mg alloys.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4257-y
Hafnia-based ferroelectrics exhibit a distinctive reverse size effect and exceptional scalability, positioning them as critical candidates for CMOS-compatible non-volatile memory and ferroelectric transistors, with substantial promise for advancing hardware acceleration in artificial intelligence and large-data storage technologies. However, their practical deployment is constrained by a longstanding dilemma: the difficulty in simultaneously stabilizing metastable polar phases and ensuring long-term reliability under the high electric fields required for polarization switching. This review reinterprets this challenge through the lens of defect physics and advocates a paradigm shift from stochastic, disorder-mediated defect incorporation toward ordered, multiscale defect engineering. We systematically discuss the collective influence of point defects, line defects, planar defects, and defect-coupled structures on the phase stability, switching kinetics, and failure mechanisms in hafnia-based ferroelectrics. Controlling oxygen-vacancy states, engineering dopants via Fermi-level and chemical pressure, deploying periodic dislocation arrays, designing topological domain walls, functionalizing interfaces, and leveraging flexoelectric strain gradients constitute the core strategic toolkit. Through such ordered defect architectures, scalable performance metrics, including high remanent polarization, low coercive field, fast switching speed, and endurance exceeding 10^12 cycles, become attainable. These approaches establish a set of design principles for next-generation low-power, high-reliability ferroelectric electronics.
Environmental Chemistry•2026•DOI: 10.7524/j.issn.0254-6108.2025120801
The interaction between microplastic-derived dissolved organic matter (PSDOM) and iron oxides in soil environments can modulate its photosensitization effects, yet the underlying mechanisms remain elusive. This study investigated the influence of hematite with distinct morphologies—flake-shaped (HNPs) and cubic (HNCs)—on the photosensitization of polystyrene-derived dissolved organic matter (PSDOM). Under 500 W mercury lamp irradiation, both hematite morphologies promoted PSDOM degradation, with HNCs exhibiting superior performance: total organic carbon (TOC) decreased from 18.4 mg·L−1 to 12.3 mg·L−1 within 90 min, compared to 13.3 mg·L−1 for HNPs. Three-dimensional fluorescence spectroscopy indicated that hematite alters the humification process, thereby modifying photosensitization. Electron paramagnetic resonance (EPR) spectroscopy identified the generation of singlet oxygen (1O2), hydroxyl radicals (·OH), and carbon-centered radicals (CH3C(=O)OO·). HNCs significantly enhanced 1O2 production, while HNPs favored ·OH generation; both inhibited CH3C(=O)OO· formation. Quantitative analysis via high-performance liquid chromatography revealed that the steady-state concentration of 1O2 was highest with HNCs, reaching 2.80 times that of the PSDOM control, whereas ·OH concentration peaked with HNPs at 1.98 times the control. Notably, the steady-state concentration of 1O2 was approximately three orders of magnitude higher than that of ·OH. These findings elucidate the morphology-dependent role of hematite in PSDOM photosensitization, providing mechanistic insights into the environmental fate of microplastic-derived organic matter in complex soil systems.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-3776-9
Organic thin-film transistors (OTFTs) are fundamental building blocks for flexible electronics, offering mechanical flexibility, biocompatibility, chemical tunability, and compatibility with large-area, cost-effective fabrication. However, their widespread adoption in high-density integrated systems is hindered by the thermionic limit of carrier injection, which constrains the subthreshold swing (SS) to a minimum of 60 mV/dec at room temperature, posing a critical barrier to ultra-low-power operation. In a groundbreaking study published in Nature Electronics, Deng et al. report the realization of organic thin-film tunnel transistors (OTFTTs) that decisively break this Boltzmann tyranny. The breakthrough is enabled by an interfacial molecule decoupling strategy, introducing a high-ionization-energy molecular interlayer, N,N'-bis(2-phenylethyl)perylene-3,4:9,10-tetracarboxylic diimide (BPE-PTCDI), between the high-work-function metal oxide (MoO3) source and the p-type organic semiconductor (2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT)) channel. This interlayer passivates the interface, minimizing interfacial gap states and alleviating Fermi-level pinning, thereby creating a clean heterojunction with a lowered tunneling barrier. This facilitates efficient quantum mechanical band-to-band tunneling for carrier injection at low supply voltages, instead of relying on traditional thermionic emission. The OTFTTs exhibit sub-thermionic SS values below 60 mV/dec, enabling high electrical performance at low operating voltages. This work provides a viable pathway for beyond-thermionic electronics, with potential applications in flexible displays, wearable health monitors, brain-computer interfaces, and distributed sensor networks, addressing the critical challenge of power dissipation in flexible systems.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4030-y
In the era of artificial intelligence, efficient perception and processing of massive visual information demand advanced machine vision systems. Inspired by human visual adaptation, various optoelectronic devices have been developed, yet most rely on external gate voltages or complex circuits for dynamic sensitivity modulation. This work demonstrates an all-optically controlled biomimetic sensor based on a one-dimensional ZnO/MAPbBr3 heterojunction, achieving both positive and negative photoconductivity effects. By modulating oxygen vacancy states with ultraviolet light, the competition between intrinsic photoconduction and trap-mediated carrier capture is regulated, enabling dynamic control of visible-light photoresponse within a single device. This tunable behavior mimics scotopic adaptation (photopigment regeneration under weak illumination), photopic adaptation (photopigment bleaching in bright environments), and eyelid-like self-protection against intense light. The device operates without external gate bias or cascaded circuits, offering a promising strategy for next-generation intelligent biomimetic sensors in machine vision.