Nanoscience News (<front>)

Single-atom cocatalysts (SACs) in photocatalysis are comprehensively discussed, with a focus on often-overlooked aspects of general concepts and understanding. Key principles, challenges, and recent advancements are covered, highlighting the self-homing effect as a promising avenue for designing SACs with maximized efficiency and unexpected features.

Single-atom (SA) cocatalysts (SACs) have garnered significant attention in photocatalysis due to their unique electronic properties and high atom utilization efficiency. This review provides an overview of the concept and principles of SA cocatalyst in photocatalysis, emphasizing the intrinsic differences to SAs used in classic chemical catalysis. Key factors that influence the efficiency of SAs in photocatalytic reactions, particularly in photocatalytic hydrogen (H2) production, are highlighted. This review further covers synthesis methods, stabilization strategies, and characterization techniques for common SAs used in photocatalysis. Notably, “reactive deposition” method, which often shows a self-homing effect and thus achieves a maximum utilization efficiency of SA cocatalysts, is emphasized. Furthermore, the applications of SA cocatalysts in various photocatalytic processes, including H2 evolution, carbon dioxide reduction, nitrogen fixation, and organic synthesis, are comprehensively reviewed, along with insights into common artifacts in these applications. This review concludes by addressing the challenges faced by SACs in photocatalysis and offering perspectives on future developments, with the aim of informing and advancing research on SAs for photocatalytic energy conversion.

In this review, the authors comprehensively examine the design strategies, fabrication technologies, and diverse applications of P-CHs. By summarizing design strategies, such as molecular, network, phase, and structural engineering, and exploring both 2D and 3D fabrication techniques, it offers a comprehensive overview of P-CHs applications in diverse fields including bioelectronics, soft actuators, energy devices, and solar evaporators.

Conductive hydrogels combine the benefits of soft hydrogels with electrical conductivity and have gained significant attention over the past decade. These innovative materials, including poly(3,4-ethylenedioxythiophene) (PEDOTs)-based conductive hydrogels (P-CHs), are promising for flexible electronics and biological applications due to their tunable flexibility, biocompatibility, and hydrophilicity. Despite the recent advances, the intrinsic correlation between the design, fabrications, and applications of P-CHs has been mostly based on trial-and-error-based Edisonian approaches, significantly limiting their further development. This review comprehensively examines the design strategies, fabrication technologies, and diverse applications of P-CHs. By summarizing design strategies, such as molecular, network, phase, and structural engineering, and exploring both 2D and 3D fabrication techniques, this review offers a comprehensive overview of P-CHs applications in diverse fields including bioelectronics, soft actuators, energy devices, and solar evaporators. Establishing this critical internal connection between design, fabrication, and application aims to guide future research and stimulate innovation in the field of functional P-CHs, offering broad benefits to multidisciplinary researchers.

The declined regeneration potential of aging NPPCs fails to antagonize IVDD. The in-house-customized lipid nanoparticles efficiently introduce Klotho circRNA into NPPCs to engender a renascent phenotypic and attune the balance of ECM synthesis/catabolism. Moreover, chemokine-scavenging hydrogel reservoir in tandem with NPPCs rejuvenated NT-LNPs enlists the regenerative capacity of resident NPPCs and restoration of youthful structure and functional features to the IVD.

The decreased regeneration potential of aging nucleus pulposus resident progenitor cells (NPPCs) fails to resist intervertebral disc degeneration (IVDD), and strategies to remodel the regeneration capacity of senescent NPPC are urgently needed. A decrease in Klotho gene expression in NPPCs of both old mice and humans exacerbates the impaired regenerative functionality of NPPC. Here, an NPPC-targeted lipid thymine nanoparticle (NT-LNP) is reported for the in situ manipulation of the regenerative repair potential of NPPCs, restoration of degenerated nucleus pulposus tissue, and mitigation of IVDD. Specifically, the results showed that the in-house customized lipid nanoparticles efficiently introduced Klotho circular ribonucleic acid (circRNA) into NPPCs to engender a renascent phenotype and tuned the balance of extracellular matrix synthesis/catabolism in vitro and in vivo. Moreover, an intradiscal injectable hydrogel system that scavenges chemokines (MCP1 and IL8) in tandem with NPPCs rejuvenated NT-LNPs in the IVD, modulating the inflammatory environment and synergistically promoting the regeneration of degenerated intervertebral discs. In summary, the findings establish that NPPCs can be re-engineered to be youthful and pluripotent to maintain homeostasis and rejuvenation, thereby providing a reversible treatment strategy for IVDD with broad application in other senescence-related diseases.

A highly transparent photochromic hydrogel electrolyte is developed, which not only serves as an electrolyte for zinc anode-based electrochromic devices but also provides a photochromic effect to reduce tinted transmittance. These dual-responsive dimmers address concerns about low transmittance contrast in electrochromic devices, representing a significant step forward for high-contrast dimming in dynamic windows and AR glasses.

Electrochromism stands out as a highly promising technology for applications including variable optical attenuators, optical switches, transparent displays, and dynamic windows. The pursuit of high-contrast tunability in electrochromic devices remains a challenging goal. Here, the first photochromic hydrogel electrolyte is reported for electro- and photo-dual responsive chromatic devices that yield a high transmittance contrast at 633 nm (ΔT = 83.1%), along with a tinted transmittance below 1.5%. Such high-contrast devices not only hold great promise for dynamic windows but also enable seamless transitions between transparent augmented reality (AR) glass and opaque virtual reality (VR) glass. These findings introduce an innovative strategy for the design of high-contrast dimmers, opening new avenues for the development of chromatic devices.

The combination of emulsions, slip casting, and inorganic particle loaded suspensions forms a processing platform that allows the controlled fabrication of intricate inorganic/inorganic composites. This new platform can be used for example to produce strong and lightweight porous samples with pores coated by a conformal layer of a second material or tough fiber-reinforced composites.

Inorganic/inorganic composites are found in multiple applications crucial for the energy transition, from nuclear reactors to energy storage devices. Their microstructures dictate their properties from mass transport to fracture resistance. Consequently, there has been a multitude of processes developed to control them, from powder mixing and the use of short or long fibers, to tape casting for laminates up to recent 3D printing. Here, emulsions and slip casting are combined into a simpler, broadly available, inexpensive processing platform that allows for in situ control of composite microstructure while also enabling complex 3D shaping. This study shows that slip casting of emulsions triggers a two-step solvent removal, opening the possibility for the conformal coating of pores. This process is showcased by producing strong and lightweight alumina scaffolds reinforced by a conformal zirconia coating. In addition, by manipulating magnetically responsive droplets, their distribution can be controlled, allowing for the formation of inorganic fibers inside an inorganic matrix in situ during slip casting. Using this approach, alumina has been reinforced with aligned metallic iron fibers to prepare composites with a work of fracture an order of magnitude higher than the pure ceramics.

An anti-freezing acid-salt hybrid electrolyte with the stable anion−cation−H2O (Cl−−Zn2+−H2O) solvation structure is developed, which achieves unconventional proton transport through strong interactions between hydrophilic ions and H2O and improves cycling stability by avoiding severe structure destruction of α-MoO3 anodes, resulting in providing a steady power supply for the VHCF//α-MoO3 proton storage device at −80 °C.

The critical challenges in developing ultralow-temperature proton-based energy storage systems are enhancing the diffusion kinetics of charge carriers and inhibiting water-triggered interfacial side reactions between electrolytes and electrodes. Here an acid-salt hybrid electrolyte with a stable anion−cation−H2O solvation structure that realizes unconventional proton transport at ultralow temperature is shown, which is crucial for electrodes and devices to achieve high rate-capacity and stable interface compatibility with electrodes. Through multiscale simulations and experimental investigations in the electrolyte employing ZnCl2 introduced into 0.2 M H2SO4 solution, it is discovered that unique anion−cation−H2O solvation structure endows the electrolyte with low-temperature-adaptive feature and favorable water network channels for rapid proton transport. In situ XRD and multiple spectroscopic techniques further reveal that the stable 3D network structure inhibits free water-triggered deleterious electrode structure distortion by immobilizing free water molecules to achieve outstanding cycling stability. Hence, VHCF//α-MoO3 hybrid proton capacitors deliver an unexpected capacity of 39.8 mAh g−1 at a high current density of 1 A g−1 (−80 °C) and steady power supply under ultralow temperatures (96% capacity retention after 1500 cycles at −80 °C). The anti-freezing hybrid electrolyte design provides an effective strategy to improve the application of energy storage devices in ultralow temperatures.

Correlation clustering imaging (CLIM) exploits local intensity fluctuations observed by fluorescence microscopy in metal-halide perovskite films and their solar cells to generate novel contrasts uncovering the spatial dynamics of charge carrier transport, recombination losses, and material restructuring.

The instability of metal halide perovskites limits the commercialization of solar cells despite their impressive efficiencies. This instability, driven by photo-induced ion migration, leads to material restructuring, defect formation, degradation, and defect healing. However, these same “unwanted” properties enable to propose Correlation Clustering Imaging (CLIM), a technique that detects local photoluminescence (PL) fluctuations through wide-field fluorescence microscopy. It is shown that such fluctuations are present in high-quality perovskites and their corresponding solar cells. CLIM successfully visualizes the polycrystalline grain structure in perovskite films, closely matching electron microscopy images. The analysis of fluctuations reveals a dominant metastable defect responsible for the fluctuations. In solar cells in short-circuit conditions, these fluctuations are significantly larger, and corresponding correlated regions extend up to 10 micrometers, compared to 2 micrometers in films. It is proposed that the regions resolved by CLIM in solar cells possess a common pool of charge extraction channels, which fluctuate and cause PL to vary. Since PL fluctuations reflect non-radiative recombination processes, CLIM provides valuable insights into the structural and functional dynamics of carrier transport, ion migration, defect behavior, and recombination losses. CLIM offers a non-invasive approach to understanding luminescent materials and devices in operando, utilizing contrasts based on previously untapped properties.

A stress-electric coupling hydrogel microsphere is developed to restore low-loss transduction between tissues. The synergistic effects of the molecular slippage mechanism of slide-ring structure, the conjugated π-electron movement of polypyrrole, and the piezoelectric properties of barium titanate minimize the energy loss during electromechanical conversion between tissues, enhance chondrogenic differentiation of stem cells and remodel inflammatory microenvironment, thereby promoting osteoarthritis treatment.

High transductive loss at tissue injury sites impedes repair. The high dissipation characteristics in the electromechanical conversion of piezoelectric biomaterials pose a challenge. Therefore, supramolecular engineering and microfluidic technology is utilized to introduce slide-ring polyrotaxane and conductive polypyrrole to construct stress-electric coupling hydrogel microspheres. The molecular slippage mechanism of slide-ring structure stores and releases mechanical energy, reducing mechanical loss, the piezoelectric barium titanate enables stress-electricity conversion, and conjugated π-electron movement in conductive network improves the internal electron transfer efficiency of microspheres, thereby reducing the loss in stress-electricity conversion for the first time. Compared to traditional piezoelectric hydrogel microspheres, the stress-electric coupling efficiency of low-dissipation microspheres increased by 2.3 times, and the energy dissipation decreased to 43%. At cellular level, electrical signals generated by the microspheres triggered Ca2+ influx into stem cells and upregulated the cAMP signaling pathways, promoting chondrogenic differentiation. Enhanced electrical signals induced macrophage polarization to the M2 phenotype, reshaping inflammation and promoting tissue repair. In vivo, the low-dissipation microspheres restored low-loss transduction between tissues, alleviated cartilage damage, improved behavioral outcomes, and promoted the treatment of osteoarthritis in rats. Therefore, this study proposes a new strategy for restoring low-loss transduction between tissues, particularly in mechanically sensitive tissues.

In this work, the metal-organic framework (MOF) glass, i.e., Zn-ZIF62 glass, is used to overcome the inadequate structural stability and rapid failure of the Zn-ZIF62 crystal. When prepared as an artificial interlayer on the Zn metal anode, the heightened configuration freedom of MOF glass endows the stress-resisted ion transport and the extended Zn2+ ion diffusion pathway, thus achieving high-performance aqueous zinc-ion batteries.

The practical application of safe and cost-effective aqueous zinc-ion batteries is enhanced by the metal-organic frameworks (MOFs), which possess tunable porous structures and chemical compositions that can facilitate the desolvation and transport of Zn2+ ions at the anode interface. However, ensuring the structural stability and operational life of crystalline MOFs in batteries remains a challenge. Here, a breakthrough is presented in tackling this dilemma. A MOF glass interlayer, specifically the ZIF-62 glass interlayer, is designed and fabricated for the Zn anode. The integration of this interlayer endows the Zn anode with a remarkable cyclic lifespan. It also achieves outstanding cyclability in Zn||MnO2 full-cell with limited Zn excess, showing no capacity decay after 600 cycles at 0.5 A g−1, and in a Zn||iodine pouch battery with a mass loading of 12.85 mg cm−2. This superior cyclicity is attributed to the ease of distortion of Zn[ligand]4 tetrahedra and the reduced likelihood of disconnection between adjacent tetrahedra within the glass interlayer, as compared to its crystalline counterpart. The unique structure of ZIF-62 glass provides an increased degree of configurational freedom, allowing it to withstand mechanical stress and extend the Zn2+ ion diffusion pathway. This ensures high cycling stability and rapid interfacial diffusion kinetics.

A multifunctional quasi-homogeneous catalyst strategy with Ru-loaded amino-phenanthroline-based carbonized polymer dots (RuApCPDs) well-dispersed in the electrolyte is developed. Together with the ability to facilitate Li2O2 formation and decomposition, modify electrolytes, and protect Li metal anode, RuApCPDs render Li-O2 batteries with comprehensively improved performance, offering brand-new catalyst design strategies for Li-O2 batteries.

Li-O2 batteries have been considered as a kind of prospective next-generation batteries due to their ultrahigh energy densities. However, limited capacities, high charge overpotentials, and short lifetime are troubling obstacles for realizing their real-world implementation. Common strategies, including introducing solid-state catalysts (SSCs) and redox mediators (RMs), are insufficient to solve these issues. Herein, Ru-loaded amino-phenanthroline-based carbonized polymer dots (RuApCPDs) integrating the catalytic activity of SSCs with the mobility of RMs have been designed to behave as quasi-homogeneous catalysts in the electrolyte. Their mobile nature can ensure the avoidance of complete coverage of active sites, and the catalytic ability decreases the charge overpotential through co-deposition with the discharge products. Additionally, the RuApCPDs can also adjust the Li+ solvation structure and well protect the Li metal anodes with high stability. As a result, the introduction of RuApCPDs leads to a fivefold increase in discharge capacity, a low charge voltage of 3.75 V, and a running life of 168 cycles (79 cycles without RuApCPDs). The multifunctional quasi-homogeneous catalyst developed here demonstrates its advantageous potential as a new catalytic strategy for bringing Li-O2 batteries to become a viable technology.

Aluminum doping strategy is used to form less aggregated structural domains, creating a favorable environment for the precipitation of nanoscale polycrystalline CaSiO3. Through the process of anomalous grain growth, the nanoscale α-CaSiO3 crystals are fully absorbed, rearranged, and transformed into micrometer-sized single-crystalline β-CaSiO3. The highly ordered layered structure of β-CaSiO3 provides efficient pathways for ion and electron transport, reducing its dielectric constant, while the single-crystalline structure enhances the mechanical properties of the electronic substrate.

β-CaSiO3 based glass-ceramics are among the most reliable materials for electronic packaging. However, developing a CaSiO3 glass-ceramic substrate with both high strength (>230 MPa) and low dielectric constant (<5) remains challenging due to its polycrystalline nature. The present work has succeeded in synthesizing single-crystalline β-CaSiO3 for a high-performance glass-ceramic substrate. This is accomplished by introducing Al3+ into the CaO-B2O3-SiO2 glass system, and by optimizing the sintering condition. Al3+ doping facilitates a heterogeneous network structure that energetically favors the precipitation of polycrystalline particles, including nanosized β-CaSiO3 crystals and sub-nanosized α-CaSiO3 crystals. As the sintering temperature increases, the nano α-CaSiO3 crystals (2–10 nm) are gradually absorbed by the β-CaSiO3 crystals. Through atomic rearrangement, α-CaSiO3 crystals transform into micrometer-sized single crystal β-CaSiO3 (1–2 µm) with layered structure. The low temperature co-fired β-CaSiO3 glass-ceramics exhibit exceptional properties, including a low dielectric constant of 4.04, a low dielectric loss of 3.15 × 10−3 at 15 GHz, and a high flexural strength of 256 MPa. This work provides a new strategy for fabricating high-performance single-crystalline glass-ceramics for electronic packaging and other applications.

This work demonstrates sunlight-triggered perpetual flipping of halide perovskite nanoplatelets between stacked and scattered configurations, under light and dark, respectively. The photo-switchable mechanical response is driven by sulfide linkage dynamics and accompanied by a brown-to-red color change. The switchable control over electric current and reversible topographical oscillations offers possibilities for nanorobotics, nanoscale switches, and sensors.

Advancements in stimuli-driven nanoactuators necessitate the discovery of photo-switchable, self-contained semiconductor nanostructures capable of precise mechanical responses. The reversible assembly of 0D Cs3Bi2I9 halide perovskite nanoplatelets (NPLs) between stacked and scattered configurations are demonstrated under light and dark, respectively. This sunlight-triggered perpetual flipping of the NPLs, occurring in less than a minute, is associated with a color change between brown and red. The photomechanical response is driven by the formation and cleavage of sulfide linkages at the NPL surface. In the stacked configuration, various stacking modes create moiré superstructures, enhancing the interlayer charge distribution, and increasing the electronic conductivity and optical absorbance. This leads to a decrease in exciton binding energy from 247 meV for scattered NPLs to 162 meV for stacked NPLs, resulting in a 3.5-fold enhancement in dark current for the stacked NPL films. The switchable control over color and electric current is continuously reversible and retraceable, exhibiting a minor memory effect observed during extended cycling. The self-flipping NPL nanoactuators demonstrate reversible mechanical responses, with topographical oscillations ranging from 14 nm in scattered NPLs to 50 nm in the vertically stacked configuration. This seamless reversible nano-assembly with color interchangeability offers numerous possibilities for nanorobotics, nanoscale switches, and sensors.

Low-symmetry metasurfaces directly patterned in WS2 thin film engender topological polarization singularities in the momentum space, which strongly interact with the exciton emission from the heterogeneously integrated monolayer MoSe2. Consequently, exciton emission with controllable chirality and directionality is achieved by combining both strong exciton emission and optical field manipulation in all van der Waals metasurfaces fully based on 2D materials.

Monolayer transition metal dichalcogenides (TMDs) with strong exciton effects have enabled diverse light emitting devices, however, their Ångstrom thickness makes it challenging to efficiently manipulate exciton emission by themselves. Although their nanostructured multi-layer counterparts can effectively manipulate optical field at deep subwavelength thickness scale, these indirect band gap multi-layer TMDs are lack of strong luminescence, hindering their applications in light emitting devices. Here, the integration of monolayer TMDs is presented with nanostructured multi-layer TMDs, combining both strong exciton emission and optical manipulation in a single ultra-thin platform. Leveraging the topological polarization singularities in the all van der Waals metasurfaces, chiral exciton emission is experimentally demonstrated whose directionality can be controlled by tailoring metasurface's symmetry. These results provide an approach that can realize exciton emitting devices fully based on 2D materials with controllable polarization and directionality, and may unfold a new avenue for multi-functional 2D semiconductor light sources.

The bromide (Br−/Br3 −) redox couple is successfully activated and maximized in 2 mm lithium bromide containing electrolyte via voltage control strategy to function as de-passivaion reagent to react with Li2O and wrapped Li0 species, which provide more accessible Li+ ions and restore the decayed capacity of fast-charging LiFePO4||Graphite cells.

Fast-charging lithium-ion batteries (LIBs) are essential for electric vehicles (EVs) to compete with conventional gasoline ones in terms of charging viability, yet the aggressive capacity drop in fast-charging scenarios gives rise to concerns regarding durability and sustainability. Herein, it is clarified that for fast-charging batteries, the excessive lithium (Li) plating on graphite anode inevitably brings capacity fading, and the concurrent accumulation of Li2O-dominant passivation species that form dead Li is the main reason for their poor rechargeability. To refresh the passivated graphite, a voltage-induced activation mechanism is developed to leverage bromide (Br−/Br3 −) redox couple for Li2O and isolated Li0 activation in situ. Along with a tiny amount of lithium bromide (LiBr) added into the electrolyte, the cut-off voltage of activation processes is controlled to initiate and maximize the effectiveness of Br−/Br3 − redox couple. The capacity of degraded fast-charging cells can increase from lower than 30 to ≈118 mAh g−1 before and after the activation, respectively. Notably, the process is not one-off; a subsequent activation is feasible. For the same battery that suffered from another round of fast charging, this design still restores the reversible capacity to ≈100 mAh g−1. Such a voltage-mediated mechanism can effectively prolong the service life of practical fast-charging batteries.

A COF-based biomimetic artificial photosynthesis system integrates ATP synthase and a light-responsive photoacid to generate a proton gradient driving ATP production. The system demonstrates regenerative ATP synthesis through repeated light on/off cycles, enabling the biocoupling of monosaccharides into disaccharides and showcasing a sustainable approach for converting solar energy into chemical energy.

Biomimetic photosynthesis, which leverages nanomaterials with light-responsive capabilities, represents an innovative approach for replicating natural photosynthetic processes for green and sustainable energy conversion. In this study, a covalent-organic framework (COF)-based artificial photosynthesis system is realized through the co-assembly of adenosine triphosphate (ATP) synthase and a light-responsive proton generator onto an imine-based COF, RT-COF-1. This system demonstrates an ATP production rate of 0.64 µmol ATP per mg protein within 90 s of light exposure and, for the first time, exhibites regenerative ATP production through multiple light on/off cycles. Furthermore, the ATP generated by the system facilitates the biocoupling of monosaccharides into disaccharides, confirming the hybrid system's capability to convert solar energy into chemical energy in the form of organic molecules. This approach shows significant potential for renewable bioenergy generation, offering precise and reliable control over biochemical processes through artificial photosynthesis.

This study unravels a self-wrinkled mechanically adaptive patterned surface (SWMAPS) by a one-step UV-curing and self-wrinkling technique. Thanks to the mechanically adaptive performance of the bionic wrinkled microstructure, the SWMAPS with both random and programmable-irradiated wrinkles can withstand more than 600 cycles of reciprocating friction, which establishes a new field of mechanically adaptive patterned surface for mechanical enhancement.

Providing mechanically adaptive performance to surfaces is significant in preserving materials from damage in variable environments, however, it has rarely been studied. Inspired by the mechanically adaptive behaviors of the surface microstructure on the carapace of desert scorpions and bark of desert tamarisks, a self-wrinkled mechanically adaptive patterned surface (SWMAPS) using one-step UV-curing and self-wrinkling technique is reported. Because of the fluorinated polyurethane photo-initiator formed by self-assembly at the top surface, UV-induced photo-crosslinking can spontaneously generate a gradient-crosslinked structure and wrinkled patterns with different morphology. With mechanically adaptive behavior originating from self-assembled fluorinated polyurethane photo-initiators, gradient-crosslinked structures, and self-wrinkled patterns, the SWMAPS remains intact under 600 cycles of reciprocating friction with little variation in the coefficient of friction and water contact angle. The SWMAPS prepared by programmable UV irradiation maintains integral under 1800 cycles of reciprocating friction with a stable friction coefficient. Furthermore, the SWMAPS is fabricated with high efficiency, regulated morphology, good surface mechanical properties, and self-recovery performance. This strategy establishes a new field of mechanically adaptive patterned surfaces, which significantly improves durability and prolongs the service life of materials in variable environments.

Herein, trimethylgermanium chloride (TGC) is introduced into the perovskite precursor solution. Comprehensive experiments find that TGC triggers the successive interactions involving the hydrolysis of Ge─Cl bond forming Ge─OH group, then forming O─H···N/O─H···I bonds. Benefiting from these successive interactions, the TGC-treated device realizes a PCE of 26.03% and 26.38% for the conventional (n-i-p) and inverted (p-i-n) FACsPbI3 PSCs with 3000 h unattenuated operation.

The rapidly increased efficiency of perovskite solar cells (PSCs) indicates their broad commercial prospects, but the commercialization of perovskite faces complex optimization processes and stability issues. In this work, a simple optimized strategy is developed by the addition of trimethylgermanium chloride (TGC) into FACsPbI3 precursor solution. TGC triggers the successive interactions in perovskite solution and film, involving the hydrolysis of vulnerable Ge─Cl bond forming Ge─OH group, then forming the hydrogen bonds (O─H···N and O─H···I) with FAI. These successive interactions effectively safeguard FA+ from decomposition, accelerate crystallization, restrict ion migration, and passivate film defects. Thus, a high-quality perovskite is obtained with the super-hydrophobic surface, maintaining the light-active phase (α-phase) even after exposure to high-humidity air (RH: 85%) for 10 days. Consequently, the TGC-treated conventional (n-i-p) and inverted (p-i-n) FACsPbI3 PSCs achieve 26.03%- and 26.38%- efficiencies, respectively, retaining unattenuated operation initial efficiency after tracking at the maximum power point (MPP) under illumination for 3000 h.

In this work, by employing multiscale modeling, the highly intrinsic anisotropic mechanical properties of the cell wall due to the layer-by-layer stacked graphene sheets are uncovered, and multiscale joint strengthening strategies are proposed to improve fatigue performance of CGA.

Despite fatigue free of monolayer graphene, its assemblies, like cellular graphene aerogels (CGA), are usually suffering of frequent fatigue and inherent strength degradation in repeated loading. In this work, by employing multiscale modeling, the highly intrinsic anisotropic mechanical properties of the cell wall due to the layer-by-layer stacked graphene sheets are uncovered, which easily trigger the unique skeleton joints damage during repeated loading and contribute the primary fatigue mechanism of CGA. Conversely, multiscale joint strengthening strategies are proposed by interlayer crosslinking and joint curvation, improving the interlayer interaction, and decreasing interlayer stress during compression, respectively, so as to effectively suppress joint damage to improve fatigue performance of CGA. This work not only clarifies the underlying fatigue mechanism of 2D cellular materials but also highlights optimal design strategies for developing anti-fatigue graphene cellular structures.

A compositionally downgraded BiFeO3 is developed to produce enhanced self-poling by introducing compressive strain. Utilizing this large-area film over a 6-inch wafer, pMUTs with 6 × 6 arrays at the device level are designed and micromanufactured. pMUT demonstrates sensitive converse piezoelectric response, even at a low frequency of 500 Hz and a high temperature of 200 °C.

Piezoelectric micromachined ultrasound transducers (pMUTs), especially those using lead-free materials, are crucial next-generation microdevices for precise actuation and sensing, driving advancements in medical, industrial, and environmental applications. Bismuth ferrite (BiFeO3) is emerging as a promising lead-free piezoelectric material to replace Pb(Zr,Ti)O3 in pMUTs. Despite its potential, the integration of BiFeO3 thin films into pMUTs has been hindered by poling issues. Here, a BiFeO3 heterostructure compositionally downgraded with Gd doping is developed to introduce compressive strain, resulting in strong self-poling. Utilizing a large-area self-poled thin film over an entire 6-inch wafer, a pMUT with a 6 × 6 array at the device level is designed and evaluated. At a resonant frequency of 21 kHz, the dynamic vibration displacement can reach 24.0 nm. At 500 Hz, far below the resonant frequency of 21 kHz, the pMUT also displays sensitive converse piezoelectric response, even at a high temperature of 200 °C. This work represents a significant breakthrough in lead-free BiFeO3 thin film for practical sensing applications, paving the way for the transformation of macro-transducers into next-generation functional microdevices.

Novel copolymer coatings dramatically reduce the formation of fibrotic tissue on medical implants, extending device longevity. In vivo screening reveals that optimizing copolymer architecture is critical for synergizing state-of-the-art antifouling and immunomodulatory antifibrotic moieties.

Immune reactions to medical implants often lead to encapsulation by fibrotic tissue and impaired device function. This process is thought to initiate by protein adsorption, which enables immune cells to attach and mount an inflammatory response. Previously, several antifibrotic materials have been either designed to reduce protein adsorption or discovered via high-throughput screens (HTS) to favorably regulate inflammation. The present work introduces antifouling immunomodulatory (AIM) copolymer coatings, which combine both strategies to effectively enhance implant protection. AIM copolymers synergistically integrate zwitterionic moieties to resist protein fouling, HTS-derived antifibrotics for immunomodulation, and silane monomers for grafting to diverse substrates including elastomers, ceramics, and metals. Interestingly, simply combining these monomers into conventional random or block copolymer architectures yielded no significant advantage over homopolymers. By contrast, an unusual polymer chain architecture — a zwitterionic block flanked by a mixed zwitterionic immunomodulatory segment — showed superior fibrosis resistance in both peritoneal and subcutaneous sites over one month in immunocompetent mice. This architecture also improved the performance of two different HTS-derived antifibrotic monomers, suggesting that tailoring AIM architectures may broadly complement immunomodulatory chemistries and provide a versatile approach to improving implant longevity.