Jing Zhang

Nature Communications, Published online: 10 July 2024; doi:10.1038/s41467-024-50255-7

Harnessing the power of cell biocatalysis for sustainable chemical synthesis requires rational integration of living cells with modern synthetic catalysts. Here, the authors introduce a silica-tiling strategy to enhance yeast cell biocatalysts by creating a nanospace with 2D silica bilayers hosting metal catalysts, enabling chemobiotic reactions without affecting cell viability.

Liquid-Enabled Soft Exoskeletons

In article number 2315161, Kadri-Ann Valdur, Indrek Must,Edoardo Sinibaldi, Barbara Mazzolai, and co-workers present a mm-scale soft exoskeleton inspired by spider legs. The exoskeleton, fabricated by two photon lithography, is enabled by the contained electrolyte solution, in terms of compliance conditioning and ion transport for muscle activation. Their technology demonstrator paves the way for liquid-enabled soft robotics systems based on physical intelligence.

Nature Physics, Published online: 09 July 2024; doi:10.1038/s41567-024-02572-3

The growth of a biofilm—a bacterial colony attached to a surface—is governed by a trade-off between horizontal and vertical expansion. Now, it is shown that this process significantly depends on the contact angle at the biofilm’s edge.

This review explores bioelectronic implantable devices, which monitor physiological signals and detect diseases early by interfacing with bodily organs. It highlights their use in neuromodulation for precise therapeutic delivery and discusses closed-loop systems that adapt treatments from real-time feedback. Integration of AI and edge computing enhances their functions, addressing challenges and future directions in bioelectronics.

Abstract

Bioelectronic implantable devices are adept at facilitating continuous monitoring of health and enabling the early detection of diseases, offering insights into the physiological conditions of various bodily organs. Furthermore, these advanced systems have therapeutic capabilities in neuromodulation, demonstrating their efficacy in addressing diverse medical conditions through the precise delivery of stimuli directly to specific targets. This comprehensive review explores developments and applications of bioelectronic devices within the biomedical field. Special emphasis is placed on the evolution of closed-loop systems, which stand out for their dynamic treatment adjustments based on real-time physiological feedback. The integration of Artificial Intelligence (AI) and edge computing technologies is discussed, which significantly bolster the diagnostic and therapeutic functions of these devices. By addressing elemental analyses, current challenges, and future directions in implantable devices, the review aims to guide the pathway for advances in bioelectronic devices.

Nature Nanotechnology, Published online: 08 July 2024; doi:10.1038/s41565-024-01710-5

Room-temperature wafer-scale thermal evaporation of 20 different polycrystalline rare-earth-metal fluoride films for their use in 2D transistors is demonstrated.

Nature Communications, Published online: 08 July 2024; doi:10.1038/s41467-024-50024-6

Explaining predictions for drug repositioning with biological knowledge graphs is a challenging problem. Here, the authors present an approach for automated biological evidence generation and show strong correlation between extracted paths and derived transcriptional changes of genes and pathways for predictions of Sulindac and Ibudilast in FragileX.

Nature, Published online: 08 July 2024; doi:10.1038/s41586-024-07764-8

Two-dimensional Perovskitoids Enhance Stability in Perovskite Solar Cells

Nature Electronics, Published online: 08 July 2024; doi:10.1038/s41928-024-01205-0

A room-temperature approach to monolithic three-dimensional thin-film integration can be used to stack ten layers of n-channel indium oxide transistors on silicon/silicon dioxide substrates, while incorporating a range of architectures.

Nature Electronics, Published online: 08 July 2024; doi:10.1038/s41928-024-01202-3

Vertical metal nanosheets with atomically flat surfaces grown with a bismuth-oxide-assisted chemical vapour deposition method can be used to make metal–oxide dielectric stacks and laminated onto two-dimensional semiconductors to create transistors with sub-1 nm capacitance-equivalent thicknesses.

Microorganisms possess remarkable locomotion abilities, making them potential candidates for micromachine propulsion. Here, the use of Chlamydomonas Reinhardtii (CR) is explored, a motile green alga, as a micromotor by harnessing its propulsive force with microtraps. The objectives include developing the microtrap structure, evaluating trapping efficiency, and investigating the movement dynamics of biohybrid micromachines driven by CRs.

Abstract

Microorganisms possess remarkable locomotion abilities, making them potential candidates for micromachine propulsion. Here, the use of Chlamydomonas Reinhardtii (CR) is explored, a motile green alga, as a micromotor by harnessing its propulsive force with microtraps. The objectives include developing the microtrap structure, evaluating trapping efficiency, and investigating the movement dynamics of biohybrid micromachines driven by CR. Experimental analysis demonstrates that trap design significantly influences trapping efficiency, with a specific trap configuration (multi-ring structure with diameters of 7 µm – 10 µm – 13 µm) showing the highest effectiveness. The micromachine empowered with two CRs facing the same direction exhibits complex, random-like motion with yaw, pitch, and roll movements, while the micromachine with four CRs in a circular position each facing the tangential direction of the circle demonstrates controlled rotational motion. These findings highlight the degree of freedom and movement potential of biohybrid micromachines.

The concept of graphenization – stabilization of layered materials at the monolayer limit – is employed to design a new 2D honeycomb magnet, GdAlSi. The monolayer films of layered GdAlSi synthesized on Si manifest an easy-plane ferromagnetic order controlled by low magnetic fields – a fingerprint of 2D ferromagnetism. Remarkably, the emerging ferromagnetism exhibits a non-monotonic evolution with the number of monolayers.

Abstract

2D magnets are expected to give new insights into the fundamentals of magnetism, host novel quantum phases, and foster development of ultra-compact spintronics. However, the scarcity of 2D magnets often makes a bottleneck in the research efforts, prompting the search for new magnetic systems and synthetic routes. Here, an unconventional approach is adopted to the problem, graphenization – stabilization of layered honeycomb materials in the 2D limit. Tetragonal GdAlSi, stable in the bulk, in ultrathin films gives way to its layered counterpart – graphene-like anionic AlSi layers coupled to Gd cations. A series of inch-scale films of layered GdAlSi on silicon is synthesized, down to a single monolayer, by molecular beam epitaxy. Graphenization induces an easy-plane ferromagnetic order in GdAlSi. The magnetism is controlled by low magnetic fields, revealing its 2D nature. Remarkably, it exhibits a non-monotonic evolution with the number of monolayers. The results provide a fresh platform for research on 2D magnets by design.

Via a co-templating and interfacial tension-tuned approach, ultrathin silica nanosheets showing high and tunable flexibility are fabricated, with surface chemistry-modulated interaction with mammalian cells.

Abstract

Flexibility of nanomaterials is challenging but worthy to tune for biomedical applications. Biocompatible silica nanomaterials are under extensive exploration but are rarely observed to exhibit flexibility despite the polymeric nature. Herein, a facile one-step route is reported to ultrathin flexible silica nanosheets (NSs), whose low thickness and high diameter-to-thickness ratio enables folding. Thickness and diameter can be readily tuned to enable controlled flexibility. Mechanism study reveals that beyond the commonly used surfactant, the “uncommon” one bearing two hydrophobic tails play a guiding role in producing sheeted/layered/shelled structures, while addition of ethanol appropriately relieved the strong interfacial tension of the assembled surfactants, which will otherwise produce large curled sheeted structures. With these ultrathin NSs, it is further shown that the cellular preference for particle shape and rigidity is highly dependent on surface chemistry of nanoparticles: under high particle-cell affinity, NSs, and especially the flexible ones will be preferred by mammalian cells for internalization or attachment, while this preference is basically invalid when the affinity is low. Therefore, properties of the ultrathin silica NSs can be effectively expanded and empowered by surface chemistry to realize improved bio-sensing or drug delivery.

Nature Communications, Published online: 06 July 2024; doi:10.1038/s41467-024-49839-0

Printing features with half pitch size of less than 10 nm by block copolymer lithography is challenging. Here, the authors employ directed self-assembly on tailored block co-polymers and achieved line pattern of 15.1 nm which corresponds to 7.6 nm half pitch size.

A biomass chitin nanofiber separator is developed for aqueous zinc-Ion batteries via a simple, low-cost, and scalable strategy. The separator can facilitate the desolvation of Zn²⁺ ions and regulate the homogeneous Zn deposition, thereby effectively inhibiting the formation of Zn dendrites and side reactions.

Abstract

Aqueous zinc-ion batteries (ZIBs) have generated extensive research attention for stationary energy storage, due to their advantaged superiority in terms of inherent safety, low cost, and eco-friendliness. However, uncontrollable dendrite growth and side reactions of the Zn anode affect the cycle life of ZIBs. Conventional separators are almost ineffective in inhibiting these issues. Herein, a chitin nanofiber membrane separator is developed to tackle these issues via a simple, low-cost, and scalable strategy. The obtained separator exhibits abundant zincophilic functional groups, homogeneous nanopores, and excellent mechanical properties, which facilitate the desolvation of hydrated Zn²⁺ ions, improve the Zn²⁺ transference number, and homogenize the ion flux, simultaneously. Moreover, the separator can also reduce the deposition barrier, and accelerate Zn²⁺ deposition kinetics. Therefore, Zn dendrites and harmful side reactions are effectively and synchronously suppressed, enabling the assembled ZIBs with an ultralong cycle life and good rate capability. Impressively, the assembled Zn-MnO₂ pouch cell exhibits excellent stability and safety under various external damages. The above highlights mark a significant step toward the practical application of ZIBs.

Ultralong room temperature phosphorescence, thought only to be accessible in a small number of compounds, is ubiquitously activated in 22 common organic chromophores. Dispersing them as submicron aggregates in a rigid polymer matrix suppresses nonradiative recombination by limiting intramolecular motion and minimizes triplet–triplet annihilation typically seen in the bulk. These films can glow for up to 10 s after ceasing excitation.

Abstract

Organic small molecules that exhibit second-scale phosphorescence at room temperature are of interest for potential applications in sensing, anticounterfeiting, and bioimaging. However, such materials systems are uncommon—requiring millisecond to second-scale triplet lifetimes, efficient intersystem crossing, and slow rates of nonradiative recombination. Here, a simple and scalable approach is demonstrated to activate long-lived phosphorescence in a wide variety of molecules by suspending them in rigid polymer hosts and annealing them above the polymer's glass transition temperature. This process produces submicron aggregates of the chromophore, which suppresses intramolecular motion that leads to nonradiative recombination and minimizes triplet–triplet annihilation that quenches phosphorescence in larger aggregates. In some cases, evidence of excimer-mediated intersystem crossing that enhances triplet generation in aggregated chromophores is found. In short, this approach circumvents the current design rules for long-lived phosphors, which will streamline their discovery and development.

An untethered soft crawling robot driven by wireless power transfer is proposed. The receiving coil receives energy and supplies the electrothermal responsiveness to drive the robot's crawling. It is also employed to equip the robot with localization, ID recognition, and sensing capabilities. This work provides an innovative and promising strategy for the design and integration of soft crawling robots.

Abstract

Soft robots based on flexible materials have attracted the attention due to high flexibility and great environmental adaptability. Among the common driving modes, electricity, light, and magnetism have the limitations of wiring, poor penetration capability, and sophisticated equipment, respectively. Here, an emerging wireless driving mode is proposed for the soft crawling robot based on wireless power transfer (WPT) technology. The receiving coil at the robot's tail, as an energy transfer station, receives energy from the transmitting coil and supplies the electrothermal responsiveness to drive the robot's crawling. By regulating the WPT's duration to control the friction between the robot and the ground, bidirectional crawling is realized. Furthermore, the receiving coil is also employed as a sensory organ to equip the robot with localization, ID recognition, and sensing capabilities based on electromagnetic coupling. This work provides an innovative and promising strategy for the design and integration of soft crawling robots, exhibiting great potential in the field of intelligent robots.

Aiming for structural enhancements, tunable band-to-band tunneling and conducting path transition are achieved in the local-control-gate (LCG) transistor based on MoTe₂/MoS₂ heterostructure. This is not only verified effectively by qualitative and intuitive analyses in density functional theory (DFT)-assisted technology computer-aided design (TCAD) simulations, but also shows great potential for multivalued logic applications.

Abstract

Transition metal dichalcogenide (TMD) material-based heterostructures have exhibited great potential for building advanced architectures in novel logic devices. A local-control-gate (LCG) transistor based on MoTe₂/MoS₂ heterostructure is fabricated and analyzed, illustrating its tunable electrical characteristics and achieving band-to-band tunneling (BTBT) enhancement with an improved peak-to-valley current ratio (PVCR) value of 3.04. Compared to the basic dual-gate tunnel field-effect transistor (TFET) structure, adding LCG at the bottom not only isolates defect-induced doping effects from the deposition of top gate dielectrics, but also paves the way for broader applications in multivalued logic and artificial intelligence. Aiming to further verify the operating mechanism of conducting path transition and electrical characteristic trends, commercial technology computer-aided design (TCAD) is systematically employed assisted by density functional theory (DFT). So that the transition of conducting paths in the heterostructure channel including interlayer quantum effects can be visibly demonstrated while applying various voltages to the LCG. In summary, this work highlights the feasibility of a new LCG structure with tunable electrical characteristics and presents DFT-assisted TCAD simulations for effective verifications.

Nature, Published online: 03 July 2024; doi:10.1038/d41586-024-02146-6

For the first time, scientists identify individual brain cells linked to the linguistic essence of a word.

Nature, Published online: 03 July 2024; doi:10.1038/s41586-024-07588-6

Three-dimensional photo-printable resin chemistry yields an elastomer with tensile strength of 94.6  MPa and toughness of 310.4  MJ  m−3, both of which far exceed that of any three-dimensional printed elastomer.

A feasible strategy for fabricating surface patterns combines the advantages of top-down and bottom-up approaches, avoiding complex processes, and the prepared microstructures can be dynamically controlled. The surface patterns can also be reversibly erased or concealed in specific application. This system exhibits in situ dynamic characteristics and offers possibilities for future nanotechnologies beyond conventional microfabrication techniques.

Abstract

Patterning polymeric materials with controllable microstructures can meet diversified requirements and realize promising applications. Exploring micro-/nano-pattern methodology offers possibilities for future techniques, however, the self-organized growth of polymeric materials has some limitations and the development of direct and noncontact patterning processes is still challenging. In this work, the study presents a facile strategy for endowing polymers with spatially regulated microstructures by direct photo-printing, which incorporates both advantages of typical top-down and bottom-up approaches. By employing the photodimerization of anthracene-containing semi-crystallized polymers, the gradient crosslinking results in a mismatch of thermal expansion coefficients between the crosslinked surface and the uncrosslinked bottom layer. After heating treatment, constrained by the crosslinked surface, the uncrosslinked bottom polymer of the molten state in the exposed region tends to flow and migrate toward the unexposed region, similar to a volcanic eruption, which accurately determines the height and morphology of pattern. Besides, the well-defined patterns can controllably grow upon thermal treatment due to phase transformation and migration. The versatility of the proposed strategy not only provides a brand-new reliable platform to pattern functional materials with photo-regulated and reversible microstructures, but also promotes the development of smart materials that can find applications in information safety, reversible microfluidics, and electronic devices.

In this review, the recent advances in silicon-based room temperature Terahertz (THz) detectors using silicon-on-insulator substrates are presented, demonstrating their great potential to facilitate high performance, low power consumption, and scalability — qualities essential for advancing next-generation photon detection technologies.

Abstract

In recent years, silicon-based room temperature Terahertz (THz) detectors have become the most optimistic research area because of their high speed, low cost, and unimpeded compatibility with mainstream complementary metal-oxide-semiconductor (CMOS) device technologies. However, Silicon (Si) suffers from low responsivity and high noise at THz frequencies. In this review, the recent advances in Si-based THz detectors using silicon-on-insulator (SOI) substrates are presented. These offer several advantages over bulk counterparts, such as reduced parasitic capacitance, enhanced electric field confinement, and improved thermal isolation. The different types of THz detectors exploiting SOI substrate, such as conventional metal-oxide-semiconductor field effect transistors (MOSFETs), junction-less MOSFETs, junction-less nanowires field effect transistors (JLNWFETs), micro-electromechanical system (MEMS), metal-semiconductor-metal (MSM) structures, and single electron transistor (SET), are discussed, and their key performances in terms of responsivity, noise equivalent power (NEP), bandwidth, and dynamic range are compared. The challenges and opportunities for further improvement of SOI THz detectors, such as device scaling, integration, and modulation, are also highlighted. This review may offer compelling evidence supporting the idea that SOI THz detectors have the potential to facilitate high performance, low power consumption, and scalability—qualities essential for advancing next-level technologies.

Considering that most colors fade with time, this work develops an additive approach to diversify colors over time. This color enrichment is realized by operando observation and measurement of the real-time growth of subwavelength metallic nanoarchitectures during 3D nanoprinting. The dimensions and geometries of these growing nanoarchitectures change in real time, thereby generating a magnificent library of time-varying colors.

Abstract

While artificial 3D nanostructures can generate precise and flexible coloration, their real-time color changes during 3D nanoprinting remain unexplored owing to the inherent challenges of in situ transient measurements and observations. In this study, a 3D-printing system which supports the operando observation/measurement of the color dynamics of subwavelength metallic nanoarchitectures fabricated in real time is developed and evaluated. During 3D printing, the dimensions and geometries of the 3D nanostructures grow over time, producing a large library of optical spectra associated with real-time color changes. Only a timer is needed to define the expected colors from a single 3D print run. Fin-like nanostructures are used to toggle colors based on the polarization effect and produce color gradients. Based on structural coloration, nanoarchitectures are designed and printed to animate desired color patterns. Moreover, the resulting color dynamics can also serve as an operando identifier for real-time structural information during 3D nanoprinting. A single print run enables the efficient creation of a comprehensive library of desired colorations owing to the flexibility in time-dependent controllability and 3D geometries at the subwavelength scale. 3D nanoprinted plasmonic structures exhibiting time-varying colorations (4D printing of colors) uniquely redefines the coloring stategy, offering considerable potential for numerous applications.

An innovative microfabrication methodology integrating the principles of scanning probe microscopy and local anodic corrosion is proposed to manufacturing freeform surface at gallium arsenide. The etching rate is well controlled by predetermined voltages throughout the scanning motion, resulting high machining accuracy, and demonstrating its competitiveness in the fabrication of functional optical device directly on semiconductor wafers.

Abstract

Two challenges should be overcome for the ultra-precision machining of micro-optical element with freeform curved surface: one is the intricate geometry, the other is the hard-to-machining optical materials due to their hardness, brittleness or flexibility. Here scanning electrochemical probe lithography (SECPL) is developed, not only to meet the machining need of intricate geometry by 3D direct writing, but also to overcome the above mentioned mechanical properties by an electrochemical material removal mode. Through the electrochemical probe a localized anodic voltage is applied to drive the localized corrosion of GaAs. The material removal rate is obtained as a function of applied voltage, motion rate, scan segment, etc. Based on the material removal function, an arbitrary geometry can be converted to a spatially distributed voltage. Thus, a series of micro-optical element are fabricated with a machining accuracy in the scale of 100 s of nanometers. Notably, the spiral phase plate shows an excellent performance to transfer parallel light to vortex beam. SECPL demonstrates its excellent controllability and accuracy for the ultra-precision machining of micro-optical devices with freeform curved surface, providing an alternative chemical approach besides the physical and mechanical techniques.