Bitao Liu

Rehabilitation medicine is an essential component of universal health coverage, while emerging electronic skin offers new opportunities for portable and personalized healthcare. However, flexible pressure sensors still face trade‐offs among sensitivity, detection range, and stability, and gas sensors remain challenged by low‐concentration detection and environmental robustness. Herein, a biomimetic “Thalia dealbata” microstructured hydrophobic polypyrrole/polydimethylsiloxane (S@PPy/PDMS) composite sensor was fabricated through a one‐step template method and controllable in situ polymerization. The biomimetic PDMS microstructure enhances pressure response, while conductive and NH ₃ ‐sensitive PPy enables dual‐mode pressure and gas sensing on a single flexible platform. The sensor exhibits a wide pressure range of 0–25 kPa, a high sensitivity of 3.617 kPa ^{− 1} , and excellent durability over 19 500 compression–release cycles. It also detects NH ₃ concentrations as low as 1 ppm with stable performance over 60 days. The dual‐functional sensor enables complementary monitoring of mechanical physiological signals, including respiration, pulse, and body motion, together with metabolic information from exhaled NH ₃ . A five‐channel sensor array further decodes numerical gestures with 100% accuracy via machine learning and wireless communication. Integrating respiratory mechanical sensing with exhaled NH ₃ detection, this platform offers potential for longitudinal, noninvasive multiparametric monitoring, particularly for CKD assessment, human–machine interfaces, smart wearables, assistive technologies, and telemedicine.

Fe3+ has attracted the attention of near-infrared luminescent material researchers due to its environmental and human-friendly, non-toxic characteristics. According to the spin selection rule and parity selection rule, the near-infrared luminescence of Fe3+ originated from the 4T1→6A1 electronic transition of the d orbital is spin-forbidden and parity-forbidden. Therefore, the luminescence efficiency of Fe3+-activated near-infrared luminescent phosphors is usually very weak. We effectively eliminated the parity-forbidden effect of Fe3+ luminescence by doping Lu3+ in Y3AlGa4O12 (YAGG) and adding excess Al3+ to reduce the octahedral symmetry of the Fe3+ site, thus making the coordination environment of Fe3+ no longer have a strict inversion center. At the same time, the smaller radius of Lu3+ and Al3+ entering the lattice led to the formation of more and stronger Lu-O and Al-O bonds around Fe3+, enhancing the overall structural rigidity of the crystal and reducing the probability of non-radiative transitions. Under the influence of the asymmetric effect and the addition of non-stoichiometric elements on the coordination environment of Fe3+, the quantum efficiency of the phosphor has been tripled; Meanwhile, at 423.15 K, the thermal stability of the phosphor exhibits an anti-thermal quenching phenomenon based on the integral intensity. The synthesized phosphor not only covers the deep red light (660 nm) and far red light (730 nm) that are absorbed more by plant pigments, but also includes the near-infrared light (800-1100 nm) that is beneficial for photosynthetic bacteria absorption. Therefore, we integrated the synthesized (Y2.93Lu0.07)Al1.03Ga3.999O12:0.001Fe3+ ((YL)AGG:0.001Fe3+) phosphor powder with commercial blue light chips to prepare a pc-LED prototype and demonstrated its potential application in the field of plant growth. This work provides a reference for regulating the luminescence performance of Fe3+ and offers a more cost-effective and environmentally friendly option for LED plant lighting.

Visualizing concealed optical information by using optical materials enables the identification of hidden threats and early risk warnings. However, current approaches to multimode optical detection using fluorescent materials often employ composite luminescence from multiple rare-earth ions, significantly limiting their application. Here, Mn²⁺ ions are introduced into LiAlO₂ and ingeniously utilize multisite occupation to achieve visual detection of both UV and X-ray radiation. Compared to the yellow photoluminescence (PL) and green long-persistent luminescence (LPL) of LiAlO₂:Mn²⁺, the LPL following X-ray irradiation exhibits a similar yellow emission. However, controlling temperature changes reveals a remarkable yellow-to-green color shift in the high-temperature LPL following X-ray irradiation at temperatures above 398 K. The integration of PL with LPL establishes a novel technical paradigm for designing multimode optical visualization detection materials.

The characteristics of Fe3+ being easily accessible, cost-effective, and environmentally friendly make it the most cost-efficient activator for phosphors in phosphor- converted light-emitting diodes (pc-LEDs). The intrinsic luminescence of Fe3+ is spin-forbidden and parity-forbidden, resulting in extremely low luminous efficiency. The exposed 3d5 electrons are highly sensitive to the crystal-field environment, and its luminescence characteristics strongly depend on the symmetry and vibration modes of the host lattice. In this paper, (Y2.93Lu0.07)Al1.03Ga3.999O12:0.001Fe3+ ((YL)AGG:0.001Fe3+) phosphor that can be excited by commercial blue-light chips was synthesized through cation substitution (Y3+/Lu3+) in the garnet-structured Y3AlGa4O12 matrix and the addition of excess Al3+. Cation-site engineering reduced the symmetry of the crystal - field environment where Fe3+ is located, partially lifted the parity-forbidden of the electric-dipole transition of Fe3+, and increased the luminous efficiency of Fe3+. Its emission wavelength (600-850 nm) and emission peak (711 nm) precisely cover the deep-red (660 nm) and far-red (730 nm) regions with high absorption by plant pigments, and also increase the near-infrared band beneficial to plant growth. At 423.15 K, the thermal stability of this phosphor remains 97.33% of that at room temperature. A pc-LED prototype was fabricated by integrating this phosphor with a commercial blue-light chip, and its potential application in the field of plant growth was demonstrated. This work provides a new option for the development of pc-LED phosphors for plant lighting with Fe3+ as the activator and a new generation of compact light sources for plant lighting.

Scintillators serve as the fundamental luminescent materials in X-ray imaging and have garnered significant research interest across diverse fields, including medical diagnostics, industrial non-destructive testing, security screening, and nuclear radiation monitoring. Nevertheless, conventional single-crystal and thin-film scintillators face persistent challenges, such as limited environmental and irradiation stability, non-uniform light output distribution, and scalability constraints in large-area fabrication, which collectively hinder the advancement of high-performance X-ray imaging systems. In this study, we successfully synthesized a high-transmittance Y3Al5O12:Ce3+ (YAG:Ce3+) single crystal via the Czochralski (pulling) method. The resulting crystal exhibits a large dimension suitable for practical detector integration, an ultrafast scintillation decay time of τ = 68.31 ns, an optical transmittance exceeding 93% in the visible range, a high steady-state light yield of 189,000 photons MeV-1, and exceptional X-ray imaging spatial resolution of approximately 18 line pairs per millimeter (lp·mm-1). Furthermore, owing to the intrinsic structural robustness and compositional homogeneity of the Y3Al5O12:Ce3+ matrix, the material demonstrates outstanding resistance to radiation-induced degradation. These findings underscore the considerable potential of high-transparency single-crystal scintillators as enabling materials for next-generation, high-fidelity X-ray imaging technologies.

Fe 3+易于获取、经济高效且环保的特性使其成为荧光粉转换发光二极管 (pc-LED) 中荧光粉最具成本效益的活化剂。 Fe 3+的本征发光是自旋禁阻和宇称禁阻的，导致发光效率极低。暴露的3d 5电子对晶体场环境高度敏感，其发光特性强烈依赖于主晶格的对称性和振动模式。本文中，(Y 2.93 Lu 0.07 )Al 1.03 Ga 3.999 O12:0.001Fe 3+ ((YL)AGG:0.001Fe 3+通过在石榴石结构的Y 3 AlGa 4 O 12基体中进行阳离子取代（Y 3+ /Lu 3+ ）并添加过量的Al 3+ ，合成了可由商业蓝光芯片激发的荧光粉。阳离子位点工程降低了Fe 3+所在晶场环境的对称性，部分解除了Fe 3+电偶极子跃迁的宇称禁限，提高了Fe 3+的发光效率。其发射波长（600-850 nm）和发射峰（711 nm）精确覆盖了植物色素高吸收的深红（660 nm）和远红（730 nm）区域，并增加了有利于植物生长的近红外波段。在423.15 K下，该荧光粉的热稳定性仍保持在室温下的97.33%。通过将该荧光粉与商用蓝光芯片集成，制作了 pc-LED 原型，并展示了其在植物生长领域的潜在应用。该工作为开发以Fe 3+为激活剂的植物照明用pc-LED荧光粉和新一代紧凑型植物照明光源提供了新的选择。

Respiratory monitoring and fruit wax detection offer significant potential for personal health assessment, disease diagnosis, and the prevention of lethal virus transmission. Perovskites, recognized for facilitating the surface dissociation of water molecules, are widely employed in humidity-responsive electronics. However, inherent crystal defects critically compromise perovskite structural stability and charge transfer efficiency, degrading the device performance. To overcome these limitations, we utilized template-confined growth technology to fabricate CsAg₂I₃ perovskite microwires, achieving enhanced crystallographic stability and superior charge transport. This strategy yielded a highly stable, ultra-moisture-resistant noncontact humidity sensor exhibiting a 6.62 s response time, 4.26 s recovery time, and 5% RH detection limit. Remarkably, the sensor-maintained functionality for >60 days at 70% RH. It enables noncontact detection of finger perspiration and fruit surface moisture while achieving gesture recognition with ultrasensitive response kinetics. These capabilities establish a versatile platform for long-term respiratory monitoring, fruit wax detection, and human-computer interaction.

The oxygen evolution reaction (OER) is a critical process in proton exchange membrane (PEM) water electrolysis, but its sluggish kinetics and harsh operational environment e.g., high anodic potentials, oxidative atmosphere, and strong acidic media pose significant challenges to catalyst design. Iridium (Ir) is among the most effective catalysts for OER in acidic conditions; however, its scarcity and high cost necessitate strategies to enhance its efficiency and stability. Reducing the size of Ir nanoparticle to 3-4 nm can significantly enhance OER activity due to an increased surface area and more accessible active sites. In this study, we report the synthesis of a highly active and stable Ir/SBA15 catalyst, in which Ir nanoparticles are uniformly deposited onto mesoporous silica (SBA15). The mesoporous structure of SBA-15 facilitates uniform nanoparticle dispersion, while the incorporation of a conductive nanochain structure enhances electronic conductivity. Transmission electron microscopy (TEM) confirmed the uniform distribution of Ir nanoparticles with an average size of 3-4 nm. Electrochemical tests revealed that Ir/SBA15 exhibits high OER activity, excellent cycling stability, and improved conductivity compared to conventional Ir catalysts. These findings demonstrate that SBA15 supported Ir nanochains offer a promising pathway for efficient and durable OER catalysis in PEM electrolyzers, achieving a balance between catalytic performance, structural integrity, and long-term operational stability.