Jing Zhang

These first examples of jetting and threading microalgae in single/multi-cellular suspensions demonstrate the versatility of these platform biotechnologies, and the capacity to directly and safely, handle a range of living suspension configurations. The generated residues have a plethora of interesting applications, the primary interest in such living constructs is for their exploration for healing diabetic wounds.

Abstract

Microalgae are increasingly playing a significant role in many areas of research and development. Recent studies have demonstrated their ability to aid wound healing by their ability to generate oxygen, aiding the healing process. Bearing this in mind, the capability to spray/spin deposit microalgae in suspension (solution) or compartmentalize living microalgae within architectures such as fibers/scaffolds and beads, would have significance as healing mechanisms for addressing a wide range of wounds. Reconstructing microalgae-bearing architectures as either scaffolds or beads could be generated via electric field (bio-electrospraying and cell electrospinning) and non-electric field (aerodynamically assisted bio-jetting/threading) driven technologies. However, before studying the biomechanical properties of the generated living architectures, the microalgae exposed to these techniques must be interrogated from a molecular level upward first, to establish these techniques, have no negative effects brought on the processed microalgae. Therefore these studies, demonstrate the ability of both these jetting and threading technologies to directly handle living microalgae, in suspension or within a polymeric suspension, safely, and form algae-bearing architectures such as beads and fibers/scaffolds.

A novel spin-coating method creates light-driven microrobots (LMNRs) using bulk heterojunction organic semiconductor solar cells (OSSC). This technique uniformly coats various structures with a near-infrared (NIR)-responsive OSSC, enabling microrobots to move under NIR light. Applications include microplastic removal, cargo transport, and precise, light-guided motion.

Abstract

Emerging light-driven micro/nanorobots (LMNRs) showcase profound potential for sophisticated manipulation and various applications. However, the realization of a versatile and straightforward fabrication technique remains a challenging pursuit. This study introduces an innovative bulk heterojunction organic semiconductor solar cell (OSC)-based spin-coating approach, aiming to facilitate the arbitrary construction of LMNRs. Leveraging the distinctive properties of a near-infrared (NIR)-responsive organic semiconductor heterojunction solution, this technique enables uniform coating across various dimensional structures (0D, 1D, 2D, 3D) to be LMNRs, denoted as “motorization.” The film, with a slender profile measuring ≈140 nm in thickness, effectively preserves the original morphology of objects while imparting actuation capabilities exceeding hundreds of times their own weight. The propelled motion of these microrobots is realized through NIR-driven photoelectrochemical reaction-induced self-diffusiophoresis, showcasing a versatile array of controllable motion profiles. The strategic customization of arbitrary microrobot construction addresses specific applications, ranging from 0D microrobots inducing living crystal formation to intricate, multidimensional structures designed for tasks such as microplastic extraction, cargo delivery, and phototactic precise maneuvers. This study advances user-friendly and versatile LMNR technologies, unlocking new possibilities for various applications, signaling a transformative era in multifunctional micro/nanorobot technologies.

A single photon detector for communication wavelength (1550 nm) is demonstrated using van der Waals heterojunction. The detector exhibits an external quantum efficiency of >20% and a dark count rate less than 1 kHz while operating at room temperature. The results are important for quantum communication, sensing, and computing applications.

Abstract

Single-photon detectors (SPDs) are crucial in applications ranging from space, biological imaging to quantum communication and information processing. The SPDs that operate at room temperature are of particular interest to broader application space as the energy overhead introduced by cryogenic cooling can be avoided. Although silicon-based single photon avalanche diodes (SPADs) are well-matured and operate at room temperature, the bandgap limitation restricts their operation at telecommunication wavelength (1550 nm) and beyond. InGaAs-based SPADs, on the other hand, are sensitive to 1550 nm photons but suffer from relatively lower efficiency, high dark count rate, afterpulsing probability, and pose hazards to the environment from the fabrication process. In this work, the properties of nanomaterials that can be leveraged to address these challenges are demonstrated and a room-temperature single-photon detector capable of operating at 1550 nm is realized. This is achieved by coupling a low bandgap (≈ 350 meV) absorber (black phosphorus) to a sensitive van der Waals probe that is capable of detecting discrete electron fluctuation. The device is optimized for operation at 1550 nm and demonstrates an overall quantum efficiency of 21.4% (estimated as 42.8% for polarized light), and a minimum dark count of ≈ 720 Hz at room temperature.

Nature, Published online: 19 June 2024; doi:10.1038/d41586-024-01642-z

A sheet of graphene sandwiched between electrolytes can host independently tunable proton and electron currents — setting the stage for a device that serves both computer-memory and logic functions.

Nature, Published online: 19 June 2024; doi:10.1038/s41586-024-07563-1

A method for topological automatic cell type classification across subcellular resolution spatial transcriptomic platforms is proposed, resolving cell type information and locating sparsely dispersed cells in human kidney and mouse kidney and brain.

The field-effect transistor (FET) is a cornerstone of modern electronics, pivotal in the development of compact and efficient integrated microprocessors and memory storage devices capable of low-power operation. At the heart of a FET is a semiconductor ...

Nature Physics, Published online: 19 June 2024; doi:10.1038/s41567-024-02532-x

The collective migration of cell clusters is modulated by substrate geometry through a combination of velocity and polarity alignment.

Nature Communications, Published online: 21 June 2024; doi:10.1038/s41467-024-49561-x

Author Correction: Waveguide-integrated twisted bilayer graphene photodetectors

Nature Communications, Published online: 21 June 2024; doi:10.1038/s41467-024-48792-2

Quantifying animal behavior is crucial in various fields such as neuroscience and ecology, yet we lack data-efficient methods to perform behavioral quantification. Here, the authors provide new unified models across 45+ species without manual labeling, thus enhancing analysis in behavioral studies.

Nature Synthesis, Published online: 20 June 2024; doi:10.1038/s44160-024-00560-2

Cell-based polymerization offers a promising avenue for integrating synthetic chemistry with biological systems. By leveraging cellular machinery, native chemical environments and external stimuli, the in situ-synthesized polymers hold the potential to impact diverse biomedical research domains, from the regulation of cell behaviour to targeted therapeutics.

Simple and versatile strategies are proposed for synthesis of super-uniform COF colloidal particles and self-assembly of them into 1D supraparticles, 2D ordered mono/multilayers, and 3D COF films. These superstructures demonstrate long-range periodicity while preserving their porosity and high specific surface area. The feasibility of the strategies is examined with different types of COFs.

Abstract

Precise self-assembly of colloidal particles is crucial for understanding their aggregation properties and preparing macroscopic functional devices. It is currently very challenging to synthesize and self-assemble super-uniform covalent organic framework (COF) colloidal particles into well-organized multidimensional superstructures. Here, simple and versatile strategies are proposed for synthesis of super-uniform COF colloidal particles and self-assembly of them into 1D supraparticles, 2D ordered mono/multilayers, and 3D COF films. For this purpose, several self-assembly techniques are developed, including emulsion solvent evaporation, air-liquid interfacial self-assembly, and drop-casting. These strategies enable the superstructural self-assembly of particles of varying sizes and species without any additional surfactants or chemical modifications. The assembled superstructures maintain the porosity and high specific surface area of their building blocks. The feasibility of the strategies is examined with different types of COFs. This research provides a new approach for the controllable synthesis of super-uniform COF colloidal particles capable of self-assembling into multidimensional superstructures with long-range order. These discoveries hold great promise for the design of emerging multifunctional COF superstructures.

The negligible spin-orbit interaction in graphene poses a challenge in inducing Dzyaloshinskii–Moriya interaction (DMI) in a ferromagnet close to graphene. Here, it is shown that in a graphene/Fe₃GeTe₂ system, significant DMI emerges from an interfacial electric field, driven by charge density imbalance and broken inversion symmetry.

Abstract

Dzyaloshinskii–Moriya interaction (DMI) is shown to induce a topologically protected chiral spin texture in magnetic/nonmagnetic heterostructures. In the context of van der Waals spintronic devices, graphene emerges as an excellent candidate material. However, due to its negligible spin-orbit interaction, inducing DMI to stabilize topological spins when coupled to 3d-ferromagnets remains challenging. Here, it is demonstrated that, despite these challenges, a sizeable Rashba-type spin splitting followed by significant DMI is induced in graphene/Fe₃GeTe₂. This is made possible due to an interfacial electric field driven by charge asymmetry together with the broken inversion symmetry of the heterostructure. These findings reveal that the enhanced DMI energy parameter, resulting from a large effective electron mass in Fe₃GeTe₂, remarkably contributes to stabilizing non-collinear spins below the Curie temperature, overcoming the magnetic anisotropy energy. These results are supported by the topological Hall effect, which coexists with the non-trivial breakdown of Fermi liquid behavior, confirming the interplay between spins and non-trivial topology. This work paves the way toward the design and control of interface-driven skyrmion-based devices.

A deformable colored sound display is presented by utilizing alternating-current electroluminescence (ACEL) and halide perovskite composite films. The device generates diverse colors with sound at single electric field. The association of color and sound is demonstrated by playing music and notifying the safety state.

Abstract

The association of color and sound helps human cognition through a synergetic effect like intersensory facilitation. Although soft human-machine interfaces (HMIs) providing unisensory expression have been widely developed, achieving synchronized optic and acoustic expression in one device system has been relatively less explored. It is because their operating principles are different in terms of materials, and implementation has mainly been attempted through structural approaches. Here, a deformable sound display is developed that generates multiple colored lights with large sound at low input voltage. The device is based on alternating-current electroluminescence (ACEL) covered with perovskite composite films. A sound wave is created by a polymer matrix of the ACEL, while simultaneously, various colors are produced by the perovskite films and the blue electroluminescence (EL) emitted from the phosphors in the ACEL. By patterning different colored perovskite films onto the ACELs, associating the color and the sound is successfully demonstrated by a piano keyboard and a wearable interactive device.

Defect-rich metastable MoS₂ nanozymes (1T2H-MoS₂) are designed via reduction and phase transformation in molten sodium. The clinical feasibility of 1T2H-MoS₂ via ex vivo therapeutic responses is demonstrated as a guide treatment for human breast cancer. The 1T2H-MoS₂ can function as an extracellular hydroxyl radical generator, efficiently repolarizing TAMs to the M1-like phenotype and directly killing cancer cells.

Abstract

Tumor-associated macrophages (TAMs) play a crucial function in solid tumor antigen clearance and immune suppression. Notably, 2D transitional metal dichalcogenides (i.e., molybdenum disulfide (MoS₂) nanozymes) with enzyme-like activity are demonstrated in animal models for cancer immunotherapy. However, in situ engineering of TAMs polarization through sufficient accumulation of free radical reactive oxygen species for immunotherapy in clinical samples remains a significant challenge. In this study, defect-rich metastable MoS₂ nanozymes, i.e., 1T2H-MoS₂, are designed via reduction and phase transformation in molten sodium as a guided treatment for human breast cancer. The as-prepared 1T2H-MoS₂ exhibited enhanced peroxidase-like activity (≈12-fold enhancement) than that of commercial MoS₂, which is attributed to the charge redistribution and electronic state induced by the abundance of S vacancies. The 1T2H-MoS₂ nanozyme can function as an extracellular hydroxyl radical generator, efficiently repolarizing TAMs into the M1-like phenotype and directly killing cancer cells. Moreover, the clinical feasibility of 1T2H-MoS₂ is demonstrated via ex vivo therapeutic responses in human breast cancer samples. The apoptosis rate of cancer cells is 3.4 times greater than that of cells treated with chemotherapeutic drugs (i.e., doxorubicin).

Nature Nanotechnology, Published online: 18 June 2024; doi:10.1038/s41565-024-01714-1

The use of hyperbole in scientific literature is increasing, undermining effective scientific communication.

Nature Nanotechnology, Published online: 19 June 2024; doi:10.1038/s41565-024-01687-1

Targeted black phosphorus nanosheet-based therapeutics that efficiently deliver resolvin D1 to lesional macrophages for the treatment of atherosclerosis by reducing oxidative stress and resolving inflammation have been discussed.

Nature, Published online: 18 June 2024; doi:10.1038/s41586-024-07654-z

Publisher Correction: Sex differences orchestrated by androgens at single-cell resolution

The effects of the doping of alkali metal on the sensitivity of optical temperature measurement in Li⁺/K⁺ doped Na_0.5Gd_0.5TiO₃: Yb, Er are explored by the combination of Judd-Ofelt theory and first-principles calculations. A dopant that exhibits small electronegativity and has a distinct ion radius is beneficial for improving the sensitivity of optical temperature measurement.

Abstract

In alkali metal-doped optical temperature measurement materials, the influence of the electronegativity difference of alkali metal ions on optical temperature measurement performance is rarely reported. This study investigates and analyzes the performance of optical temperature measurement of Na_0.5Gd_0.5TiO₃: Yb, Er doped with Li⁺ and K⁺ ions, utilizing the Judd-Ofelt theory and the first-principles method. The results reveal that the sensitivities increase with the increase of atomic number of doped alkali metal ions. The reason is that a difference in ionic radius between the dopant and the replaced ion decreases the symmetry of the crystal field and increases the value of Ω₂. The doping K⁺ with low electronegativity leads to an increase in the s orbital electron density of rare earth ions, thereby repelling the d orbital electrons, reducing the d electron density, and decreasing the value of Ω₆. Based on the Judd-Ofelt theory, a combination of a large Ω₂ and a small Ω₆ is expected to enhance the absolute sensitivity of optical temperature-measuring materials doped with rare earth ions. Therefore, it can be concluded that doping an ion with low electronegativity and a significant radius difference from the substitution site is beneficial for enhancing the optical temperature sensitivity.

Molecular-beam epitaxy of 2D chalcogenides typically yields small, disconnected islands, with premature onset of multilayer formation. This work reports how utilizing excited ions of a sacrificial species during the growth can dramatically enhance nucleation of the epitaxial layer, enabling growth of large-area monolayers with enhanced carrier lifetimes and facilitating the fabrication of all-epitaxial van der Waals heterostructures.

Abstract

The transition-metal chalcogenides include some of the most important and ubiquitous families of 2D materials. They host an exceptional variety of electronic and collective states, which can in principle be readily tuned by combining different compounds in van der Waals heterostructures. Achieving this, however, presents a significant materials challenge. The highest quality heterostructures are usually fabricated by stacking layers exfoliated from bulk crystals, which – while producing excellent prototype devices – is time consuming, cannot be easily scaled, and can lead to significant complications for materials stability and contamination. Growth via the ultra-high vacuum deposition technique of molecular-beam epitaxy (MBE) should be a premier route for 2D heterostructure fabrication, but efforts to achieve this are complicated by non-uniform layer coverage, unfavorable growth morphologies, and the presence of significant rotational disorder of the grown epilayer. This work demonstrates a dramatic enhancement in the quality of MBE grown 2D materials by exploiting simultaneous deposition of a sacrificial species from an electron-beam evaporator during the growth. This approach dramatically enhances the nucleation of the desired epi-layer, in turn enabling the synthesis of large-area, uniform monolayers with enhanced quasiparticle lifetimes, and facilitating the growth of epitaxial van der Waals heterostructures.

Ferromagnetic Josephson junction is important for understanding the interplay between superconductivity and ferromagnetism. The NbSe₂/Cr₂Ge₂Te₆/NbSe₂ ferromagnetic Josephson junction shows an unconventional dual-peak feature in the magnetic-field-dependent critical supercurrent due to the multidomain structure of the Cr₂Ge₂Te₆ tunnel barrier. This work helps researchers explore the interactions between Ising Cooper pairs and magnetic domains and realize practical magnetic Josephson junction devices.

Abstract

Ferromagnetic Josephson junctions play a key role in understanding the interplay between superconductivity and ferromagnetism in condensed matter physics. The magnetic domain structures of the ferromagnet in such junctions can significantly affect the tunneling of the superconducting Cooper pairs due to the strong interactions between Cooper pairs and local magnetic moments in the ferromagnetic tunnel barrier. However, the underlying microscopic mechanism of relevant quasiparticle tunneling processes with magnetic domain structures remains largely unexplored. Here, the manipulation of Cooper-pair tunneling in the NbSe₂/Cr₂Ge₂Te₆/NbSe₂ ferromagnetic Josephson junction is demonstrated by using a multidomain ferromagnetic barrier with anisotropic magnetic moments. The evolution of up-, down-magnetized domain and Bloch domain structures in Cr₂Ge₂Te₆ barrier under external magnetic fields leads to the enhancement of the critical tunneling supercurrent and an unconventional dual-peak feature with two local maxima in the field-dependent critical current curve. The phenomenon of magnetic-field-modulated critical tunneling supercurrent can be well explained by the competition between the coherence length of tunneling Cooper pairs and the size of magnetic domain walls in Cr₂Ge₂Te₆ barrier. This kind of ferromagnetic Josephson junction provides an intriguing material system for manipulating Cooper-pair tunneling by tuning the local magnetic moments within magnetic Josephson junction devices.

Nature, Published online: 17 June 2024; doi:10.1038/d41586-024-02005-4

The US$5 billion facility would be cheaper, bigger and faster to build than a similar one proposed by European scientists.

Nanoimprint lithography (NIL) is carried out in two steps to produce two sets of nanostructures, i.e., silicon metasurface and aluminum VCDGs, over an area of 4 mm by 5.2 mm. This creates subwavelength-thick, functional, multilayer metasurface polarization filter arrays with a high polarization selectivity. The chip is further integrated into a CMOS imager to demonstrate its polarimetric imaging capability.

Abstract

Optical metasurfaces, consisting of subwavelength-scale meta-atom arrays, hold great promise of overcoming the fundamental limitations of conventional optics. Due to their structural complexity, metasurfaces usually require high-resolution yet slow and expensive fabrication processes. Here, using a metasurface polarimetric imaging device as an example, the photonic structures and the Nanoimprint lithography (NIL) processes are designed, creating two separate NIL molds over a patterning area of > 20 mm² with designed Moiré alignment markers by electron-beam writing, and further subsequently integrate silicon and aluminum metasurface structures on a chip. Uniquely, the silicon and aluminum metasurfaces are fabricated by using the nanolithography and 3D pattern-transfer capabilities of NIL, respectively, achieving nanometer-scale linewidth uniformity, sub-200 nm translational overlay accuracy, and <0.017 rotational alignment error while significantly reducing fabrication complexity and surface roughness. The micro-sized multilayer metasurfaces have high circular polarization extinction ratios as large as ≈20 and ≈80 in blue and red wavelengths. Further, the metasurface chip-integrated CMOS imager demonstrates high accuracy in broad-band, full Stokes parameter analysis in the visible wavelength ranges and single-shot polarimetric imaging. This novel, NIL-based, multilayered nanomanufacturing approach is applicable to the scalable production of large-area functional structures for ultra-compact optic, electronic, and quantum devices.

Bioinspired AIE nanomedicine, constructed from AIE luminogens and biocarrier, represents a win–win integration toward fluorescence bioimaging and theranostics, and are recently developed at a tremendous pace and attracted global interest in the past few years. Herein, an integrated picture on intrinsic advantages, seminal studies, recent trends, and perspectives of such nanomaterials is offered in this review.

Abstract

Nanomedicine on the basis of aggregated-induced emission (AIE) luminogens with exceptional potency is growing into a sparkling frontier in fluorescence imaging and phototheranostics. Of particular interest is biomimetic AIE nanomedicine comprised by AIE luminogens and biocarrier, which represents a win–win integration and are recently developed at a tremendous pace, mainly benefiting from the intrinsic advantages including enhanced biocompatibility, prolonged circulation time, specific targeting ability, immune activation, and supremely extraordinary phototheranostic outputs. In view of the inexhaustible and vigorous vitality in the field, this review provides an integrated picture on biomimetic AIE nanomedicine involving the basic concepts, significant breakthroughs, and recent trends. In addition, based on the current achievements, some critical challenges and perspectives are also discussed.

Nature Communications, Published online: 14 June 2024; doi:10.1038/s41467-024-49225-w

The authors study the optimally-doped cuprate superconductor Bi2Sr2−xLaxCuO6 by nuclear magnetic resonance. They find a long-range charge density wave (CDW) order induced by uniaxial strain, showing that CDW order is a hidden order of the pseudogap state, not limited to the underdoped regime.