Jing Zhang

Nature inspires the creation of innovative adhesives, as seen in geckos and mussels, but truly replicating their functions is still a significant challenge. This review offers a comprehensive overview of biological adhesives' morphology-function relationship and biomimicry potential, summarizing design principles and offering insights into the development of excellent bioinspired adhesives.

Abstract

Nature serves as an abundant wellspring of inspiration for crafting innovative adhesive materials. Extensive research is conducted on various complex forms of biological attachment, such as geckos, tree frogs, octopuses, and mussels. However, significant obstacles still exist in developing adhesive materials that truly replicate the behaviors and functionalities observed in living organisms. Here, an overview of biological organs, structures, and adhesive secretions endowed with adhesion capabilities, delving into the intricate relationship between their morphology and function, and potential for biomimicry are provided. First, the design principles and mechanisms of adhesion behavior and individual organ morphology in nature are summarized from the perspective of structural and size constraints. Subsequently, the value of engineered and bioinspired adhesive materials through selective application cases in practical fields is emphasized. Then, a forward-looking gaze on the conceivable challenges and associated opportunities in harnessing biomimetic strategies and biological materials for advancing adhesive material innovation is highlighted and cast.

This work presents anticounterfeiting tags featuring two levels of security. The first level is achieved by recognizing hundreds to thousands of Opuntia Ficus-indica-polymethyl methacrylate (OFI-PMMA) dye features when similar tags are compared. This number drops to around ten when different tags are compared. The second security level is enhanced by sputtering ITO patches, which are visible only through terahertz (THz) spectroscopy. The varying thickness of each patch creates unique and non-reproducible tags.

Abstract

Multi-level anticounterfeiting tags have been developed using a combination of different materials. Polyvinyl alcohol (PVA) mixed with titanium dioxide (TiO₂) is used to produce flexible substrates. Fluorescent Opuntia Ficus-indica (OFI) extract dissolved with polymethyl methacrylate (PMMA) is then sprayed over the substrate to create a random, yet unique deposition of droplets. Photographs of the tags are taken under UV illumination at different angles and analyzed through the scale-invariant feature transform (SIFT) algorithm to extract their unique features. The SIFT analysis reveals hundreds to thousands of matched features when a given tag is compared with itself, whereas this number drops to tens for different tags. To enhance the security of the tags, ITO is sputtered onto one of them in the form of a pattern formed by a patch array exhibiting a specific fingerprint at terahertz (THz) frequencies. The evaluation of ITO reflectance shows that each patch array has a unique and unpredictable response stemming from its distinct electro-optical characteristics. The non-deterministic response of sprayed dye droplets and ITO patches enables the realization of two-level authentication, which is difficult to replicate at a reasonable cost. The simple manufacturing process and inexpensive materials involved make the proposed tags easily integrable into packaging.

A novel microrobot is introduced for multidrug delivery to challenging inner ear. Directionally controlled by magnetic field and propelled by ultrasound, this system efficiently penetrates the RWM with microshotgun-like ejection behavior. Such an active strategy enables precise drug delivery to the inner ear, with multidrug combinations in pre-set ratios, demonstrating a remarkable protective effect against hearing loss.

Abstract

Multidrug combination therapy in the inner ear faces diverse challenges due to the distinct physicochemical properties of drugs and the difficulties of overcoming the oto-biologic barrier. Although nanomedicine platforms offer potential solutions to multidrug delivery, the access of drugs to the inner ear remains limited. Micro/nanomachines, capable of delivering cargo actively, are promising tools for overcoming bio-barriers. Herein, a novel microrobot-based strategy to penetrate the round window membrane (RWM) is presented and multidrug in on-demand manner is delivered. The tube-type microrobot (TTMR) is constructed using the template-assisted layer-by-layer (LbL) assembly of chitosan/ferroferric oxide/silicon dioxide (CS/Fe₃O₄/SiO₂) and loaded with anti-ototoxic drugs (curcumin, CUR and tanshinone IIA, TSA) and perfluorohexane (PFH). Fe₃O₄ provides magnetic actuation, while PFH ensures acoustic propulsion. Upon ultrasound stimulation, the vaporization of PFH enables a microshotgun-like behavior, propelling the drugs through barriers and driving them into the inner ear. Notably, the proportion of drugs entering the inner ear can be precisely controlled by varying the feeding ratios. Furthermore, in vivo studies demonstrate that the drug-loaded microrobot exhibits superior protective effects and excellent biosafety toward cisplatin (CDDP)-induced hearing loss. Overall, the microrobot-based strategy provides a promising direction for on-demand multidrug delivery for ear diseases.

Proximity labeling proteomics (PLP) strategies are powerful approaches to yield snapshots of protein neighborhoods. Here, we describe a multiscale PLP method with adjustable resolution that uses a commercially available photocatalyst, Eosin Y, which upon ...

The concept of amplitude-phase dual-channel encrypted acoustic meta-hologram is introduced, which is capable of generating, encrypting, and decrypting both amplitude and phase holographic images. This unique concept of “phase holographic image” brings a new degree of freedom for meta-holograms, leading to dual-channel encrypted acoustic holography. Acoustic metasurface with simultaneous amplitude and phase modulations is employed to realize this dual-channel encryption.

Abstract

Encrypted acoustic meta-holograms have potential applications in confidential acoustic information communication, noise control, acoustic cloaking, acoustic illusion, etc. Conventional encrypted optical and acoustic meta-holograms only focus on the encrypted hologram in a single channel, viz. modulating spatial amplitude to project a holographic image. Here, the concept of an amplitude-phase dual-channel encrypted acoustic meta-hologram (DrEAM) is proposed, capable of generating, encrypting, and decrypting both amplitude and phase holographic images. This unique concept of “phase holographic image” introduces a new degree of freedom for meta-holograms, leading to dual-channel encrypted acoustic holography. Acoustic metasurface with simultaneous amplitude and phase modulations is employed to realize this dual-channel encryption. The findings may offer the possibility to increase the capacity of the encrypted acoustic meta-holograms, which can lead to practical applications in, for example, multi-channel acoustic field communications, complex noise control, and acoustic illusions.

Micro-bridge mechanical resonators are realized from crystalline LaAlO₃ transparent thin films deposited on SrTiO₃ substrates. Such resonators have low surface roughness and a high mechanical Q-factor, paving the way for the realization of oxide-based resonant sensors. They are employed as templates for the growth of superconducting YBCO single crystal thin films. A superconducting resonator having mechanical Q-factor around 180k at room temperature is demonstrated.

Abstract

Micro-mechanical resonators are building blocks of a variety of applications in basic science and consumer electronics. This device technology is mainly based on well-established and reproducible silicon-based fabrication processes with outstanding performances in term of mechanical Q-factor and sensitivity to external perturbations. Broadening the functionalities of micro-electro-mechanical systems (MEMS) by the integration of functional materials is a key step for both applied and fundamental science. However, combining functional materials with silicon-based devices is challenging. An alternative approach is directly fabricating MEMS based on compounds inherently showing non-trivial functional properties, such as transition metal oxides. Here, a full-oxide approach is reported, where a high-Tc$\rm {T_c}$ superconductor YBa₂Cu₃O₇ (YBCO) is integrated with high Q-factor micro-bridge resonators made of single-crystal LaAlO₃ (LAO) thin films. LAO resonators are tensile strained, with a stress of about 350 MPa, show a Q-factor above 200k, and have low roughness. YBCO overlayers are grown ex situ by pulsed laser deposition and YBCO/LAO bridges show zero resistance below 78 K and mechanical properties similar to those of bare LAO resonators. These results open new possibilities toward the development of advanced transducers, such as bolometers or magnetic field detectors, as well as experiments in solid state physics, material science, and quantum opto-mechanics.

This work reports a new carbon-based responsive material that unlocks the unexpectedly high vapor response speed of 9400° s⁻¹ as well as excellent enviroment tolerance. Based on this, an innovative somersaulting robot with locomotion velocity close to the level of animals is designed and constructed, representing a milestone towards achieving life-like performance in biomimetic soft robots.

Abstract

Responsive materials and actuators are the basis for the development of various leading-edge technologies but have so far mostly been designed based on polymers, incurring key limitations related to sensitivity and environmental tolerance. This work reports a new responsive material, laser-printed carbon film (LPCF), produced via direct laser transformation of a liquid organic precursor and consists of graphitic and amorphous carbons. The high activity of amorphous carbon combined with the dual-gradient structure enables the LPCF to have a actuation speed of 9400° s⁻¹ in response to the stimulus of organic vapor. LPCF exhibits a conductivity of 950 S m⁻¹ and excellent resistance to various extreme environmental conditions, which are unachievable for polymer-based materials. Additionally, an LPCF-based all-carbon soft robot that can mimic the complex continuous backward somersaulting motions without manual intervention is constructed. The locomotion velocity of the robot reaches a value of 1.19 BL s⁻¹, which is almost one to two orders of magnitude faster than that of reported soft robots. This work not only offers a new paradigm for highly responsive materials but also provides a great design and engineering example for the next generation of biomimetic robots with life-like performance.

Nature Communications, Published online: 16 July 2024; doi:10.1038/s41467-024-49586-2

Yeast is a widely used cell factory for the conversion of sugar into fuels, chemicals and pharmaceuticals. Establishing yeast as being autotrophic can enable it to grow solely on CO2 and light, and hereby yeast can be used as a wider platform for transition to a sustainable society.

GaP nanowires (NWs) with different types of doping (GaP:Si or GaP:Be) are empolyed as optical waveguides with integrated electrically-driven light sources, solving the problem of emission-to-waveguide coupling. GaP:Be NWs contain inclusions of the crystalline wurtzite phase with a direct bandgap, and, thus, these NW regions can be considered as electrically-driven nanoscale light sources monolithically integrated into GaP NW-based waveguides.

Abstract

The key components of photonic integrated circuits are nanoscale optica emitters and nanowaveguides. III-V semiconductor nanostructures are considered as the most promising material platform for these components due to highly efficient luminescence and high refractive index, but the problem of emission coupling with waveguide is to be solved. In this work, the use of GaP nanowires (NWs) with different types of doping (GaP:Si or GaP:Be) is proposed as optical waveguides with directly integrated electrically-driven light sources, solving the problem of emission-to-waveguide coupling. Single NWs are integrated with electrodes and pump electroluminescence by a tunnel junction allowing to study emission properties with nanoscale spatial resolution. Basing on the experiments on scanning tunnelling microscopy (STM), electron microscopy, time-resolved photoluminescence micro-spectroscopy, X-ray diffraction, and STM-induced electroluminescence, it is proven that GaP NWs exhibit different integrated light-source on doping type of NWs. GaP:Be NWs contain inclusion of the crystalline wurtzite phase with a direct bandgap, and, thus, these NW regions can be considered as electrically-driven nanoscale sources of light monolithically integrated into GaP NW-based waveguides. Meanwhile, GaP:Si NWs work as optical waveguides capable of efficient light generation over the entire length of NW. The developed designs are promising for construction of integrated photonic circuits.

Nature Nanotechnology, Published online: 16 July 2024; doi:10.1038/s41565-024-01712-3

Astrocytes respond to electrical stimulation via diverse calcium signalling dynamics, which are important to maintain brain function. The tunable properties of graphene oxide-based electrodes can selectively trigger these calcium signalling responses.

Mechanical metamaterials with multi-level dynamic crushing effects (MM-MLs) are designed in this study through coordinate transformation and mirror arrays. MM-ML has significant parameter controllability and can achieve different platform stress regions, ranges of Poisson's ratios, and energy absorption requirements according to the application scenario. The design scheme can provide ideas for adaptive crushing protection requirements.

Abstract

Mechanical metamaterials with multi-level dynamic crushing effects (MM-MLs) are designed in this study through coordinate transformation and mirror arrays. The mechanical effects of the diameter and length ratio of the struts and connecting rods, the Euler angles, and the cell numbers on the mechanical properties are investigated separately. MM-ML can exhibit significant two-level platform stress, and the local cells in the first platform stress stage undergo rotational motion, while the second platform stress stage mainly involves collapse compression and bending. Although increasing the length of the connecting rods can increase the range of Poisson's ratio, it will reduce the level of platform stress and energy absorption. Increasing the Euler angle will reduce the strain interval of the first platform stress and can improve the energy absorption capacity. In addition, increasing the cell number while maintaining a constant relative density can effectively enhance energy absorption. MM-ML has significant parameter controllability, can achieve different platform stress regions, different ranges of Poisson's ratios, and energy absorption requirements according to the application scenario, and can demonstrate functional diversity compared to existing research. The design scheme can provide ideas for adaptive crushing protection requirements.

Nature Communications, Published online: 16 July 2024; doi:10.1038/s41467-024-50333-w

Integrating a control interface with a quantum processor as the number of qubits scales is a significant challenge. Here the authors report a cryogenic on-chip microwave pulse generator for superconducting qubits with high degree of controllability, negligible heat load, and a small footprint.

Stimuli-responsive luminescence materials have gained booming progress in recent years. The trap-controlled property and energy storage capability to respond to external multi-stimulations through diverse luminescence pathways make them attractive in emerging multi-responsive smart platforms. This review summarizes the recent advances in trap-controlled luminescence materials for advanced multi-stimuli-responsive smart platforms, providing new insights and guidelines for the future development.

Abstract

Smart stimuli-responsive persistent luminescence materials, combining the various advantages and frontier applications prospects, have gained booming progress in recent years. The trap-controlled property and energy storage capability to respond to external multi-stimulations through diverse luminescence pathways make them attractive in emerging multi-responsive smart platforms. This review aims at the recent advances in trap-controlled luminescence materials for advanced multi-stimuli-responsive smart platforms. The design principles, luminescence mechanisms, and representative stimulations, i.e., thermo-, photo-, mechano-, and X-rays responsiveness, are comprehensively summarized. Various emerging multi-responsive hybrid systems containing trap-controlled luminescence materials are highlighted. Specifically, temperature dependent trapping and de-trapping performance is discussed, from extreme-low temperature to ultra-high temperature conditions. Emerging applications and future perspectives are briefly presented. It is hoped that this review would provide new insights and guidelines for the rational design and performance manipulation of multi-responsive materials for advanced smart platforms.

The nonfully conformal interface between the skin and electronics leads to further dissipation of weak physiological signals. This work enhances the mechanical transfer efficiency from behavior and physiological signals by introducing the stress-concentrated interface and self-adhesive hydrogel, achieving long-term stable monitoring. With the convolutional neural network algorithm for feature fusion, high-accuracy monitoring of human fatigue levels is realized.

Abstract

The great challenges for existing wearable pressure sensors are the degradation of sensing performance and weak interfacial adhesion owing to the low mechanical transfer efficiency and interfacial differences at the skin–sensor interface. Here, an ultrasensitive wearable pressure sensor is reported by introducing a stress-concentrated tip-array design and self-adhesive interface for improving the detection limit. A bipyramidal microstructure with various Young's moduli is designed to improve mechanical transfer efficiency from 72.6% to 98.4%. By increasing the difference in modulus, it also mechanically amplifies the sensitivity to 8.5 V kPa⁻¹ with a detection limit of 0.14 Pa. The self-adhesive hydrogel is developed to strengthen the sensor–skin interface, which allows stable signals for long-term and real-time monitoring. It enables generating high signal-to-noise ratios and multifeatures when wirelessly monitoring weak pulse signals and eye muscle movements. Finally, combined with a deep learning bimodal fused network, the accuracy of fatigued driving identification is significantly increased to 95.6%.

The work shows that the blue-wings of the grasshopper Coloracris azureus are a non-toxic, biobased, and biodegradable temperature sensing material. With a thickness of only ≈3 µm, the flexible blue-winged film shows reversible and steady thermochromic properties. Important for potential applications, the temperature-induced color changes are power-free and easily visible.

Abstract

Thermochromic materials have been widely investigated due to their relevance in technological applications, including anti-counterfeiting materials, fashion accessories, displays, and temperature sensors. While many organisms exhibit color changes, few studies have explored the potential of the responsive natural materials for temperature sensing, especially given the often limited and irreversible nature of these changes in live specimens. Here, it is shown that the hindwings of the blue-winged grasshopper Coloracris azureus can act as a reversible, power-free bio-thermometer, transitioning from blue to purple/red in a 30—100°C temperature range. Using microspectrophotometry, light microscopy and Raman microscopy, it is found that the blue color of the wings originates from pigmentary coloration, based on a complex of astaxanthin and proteins. The thermochromic shift from blue to red, induced by a temperature increase, is attributed to a denaturation of this carotenoprotein complex, upon which astaxanthin is released. This process is reversible upon a subsequent temperature decrease. The color changes are both swift and consistent upon temperature change, making the grasshopper's wings suitable as direct visual sensors on thermally dynamic, curved surfaces. The potential possibilities of sustainable, power-free temperature sensors or microthermometers based on biomaterials are demonstrated.

A novel high-precision transfer-printing method capable of photolithographing insoluble conducting polypyrrole electrode patterns on soft substrates is developed. High precision and good compatibility with organic functional layer are also demonstrated. Combined with a soft organic semiconductor and a dielectric, an all-organic transistor array is fabricated to realize high mobility and good 3D conformability, exhibiting great promise for next-generation soft electronics.

Abstract

The development of high-precision insoluble conducting polymer patterns for soft electronics is extremely challenging, mainly because of the incompatibility of the synthesis process with the underlying layers. In this study, a novel transfer-printing method is designed that enables the fabrication of photolithographic insoluble conducting polypyrrole (PPy) electrode patterns on soft substrates with high precision, demonstrating compatibility with various soft organic functional layers. Excellent mechanical stability, good biocompatibility, ultra-smooth surface, and outstanding conformability are observed. The photolithographic PPy electrode patterns, combined with an elastic organic semiconductor and dielectric, produce conformal all-organic transistors with mobility of 1.8 cm² V⁻¹ s⁻¹. This study paves the way to use insoluble conducting polymers to develop complex, high-density flexible patterns and offers a promising organic electrode for the new-generation soft all-organic electronics.

A strategy to amplify the conformation-variation-driven response is proposed through thermally regulating the degree of the ET from flexible ligand to Ln³⁺ acceptors in lanthanide-MOFs, where the minor conformational variations in organic linkers dramatically modulate the PL performances. These results will provide guidance for the rational construction of responsive photonic devices for advanced optical recording and high-security labels.

Abstract

Development of luminescent segmented heterostructures featuring multiple spatial-responsive blocks is important to achieve miniaturized photonic barcodes toward anti-counterfeit applications. Unfortunately, dynamic manipulation of the spatial color at micro/nanoscale still remains a formidable challenge. Here, a straightforward strategy is proposed to construct spatially varied heterostructures through amplifying the conformation-driven response in flexible lanthanide-metal-organic frameworks (Ln-MOFs), where the thermally induced minor conformational changes in organic donors dramatically modulate the photoluminescence of Ln acceptors. Notably, compositionally and structurally distinct heterostructures (1D and 2D) are further constructed through epitaxial growth of multiple responsive MOF blocks benefiting from the isomorphous Ln-MOF structures. The thermally controlled emissive colors with distinguishable spectra carry the fingerprint information of a specific heterostructure, thus allowing for the effective construction of smart photonic barcodes with spatially responsive characteristics. The results will deepen the understanding of the conformation-driven responsive mechanism and also provide guidance to fabricate complex stimuli-responsive hierarchical microstructures for advanced optical recording and high-security labels.

Nature Communications, Published online: 11 July 2024; doi:10.1038/s41467-024-50202-6

Second near-infrared (NIR-II) fluorescence imaging is promising for real-time surveillance of surgical operations, but its clinical uses have been limited by the safety and cost concerns associated with lasers or X-rays. Here the authors report the engineering and applications of white-light activatable organic nanomaterials with bright NIR-II emission.

Nature, Published online: 11 July 2024; doi:10.1038/d41586-024-02200-3

Records on the quality of the grape harvest sheds light on 600 years of weather.

Nature, Published online: 11 July 2024; doi:10.1038/d41586-024-02199-7

Strontium-based timepiece gains or loses only one second every 40 billion years.

Plasmonic nanoparticles (NPs) are used to create unique image tags as a reliable anti-counterfeit platform rapidly authenticated by machine learning protocols. Specifically, Au NPs are assembled into periodic arrays of NP clusters by template-assisted self-assembly, where dark-field optical microscopy provides the light scattering responses of NP clusters. Modular tag design is possible through selection of various NP Inks and Templates.

Abstract

Counterfeit goods are pervasive, being found in products as diverse as textiles and optical media to pharmaceuticals and sensitive electronics. Here, an anti-counterfeit platform is reported in which plasmonic nanoparticles (NPs) are used to create unique image tags that can be authenticated quickly and reliably. Specifically, plasmonic NPs are assembled into periodic arrays of NP clusters by template-assisted self-assembly (TASA), where the light scattering responses from the arrays are analyzed by dark-field optical microscopy. Tag design proved modular as plasmonic NPs with different optical responses can be selected and paired with Templates with different features (e.g., well size, well shape, and number and arrangement of wells in an array), giving access to a variety of color responses and unique images. These images can be differentiated from one another and authenticated by image analysis. Authentication methods based on shallow and deep neural networks are compared, where deep neural networks authenticated TASA tags with higher accuracy. Given the ease of tag fabrication and rapid image analysis, these platforms are ideal for on-the-fly tagging and supply-chain authentication of critical goods.

The M-FNCDs with stable TADF in the aqueous solution are successfully prepared and they show good biocompatibility, strong organelle targeting and sensitive temperature-responsive properties. Based on the above properties, M-FNCDs are used in the fields of temperature sensors, information encryption and organelle afterglow imaging.

Abstract

Thermally activated delay fluorescence (TADF) has great potential for information encryption, temperature detection, and bioimaging due to its long-lived luminescence, temperature-sensitive and high signal-to-noise ratio. However, it is still a challenge to establish TADF in aqueous environments. In this study, the composite with TADF (M-FNCDs) is prepared using fluorine-nitrogen co-doped carbon dots (FNCDs) and melamine. It is worth mentioning that the M-FNCDs show stable TADF under long-wavelength excitation (470 nm) in aqueous environments. Moreover, the M-FNCDs has distinctive temperature-responsive properties and exhibit good linear relationships in the temperature range of 77–370 K. Simultaneously, M-FNCDs suspension as the ink is utilized to realize information encryption/decryption due to their afterglow cannot be quenched in an aqueous solution. More importantly, M-FNCDs with biocompatibility can target the mitochondria and lysosomes of living cells, and for the first time achieve the high signal-to-noise ratio and low background signal afterglow imaging of organelles. This work proposes a new strategy to prepare the stable TADF in aqueous solutions under long-wavelength excitation and extend the TADF material potential applications in the future.

The doped Tm³⁺ partially replaces Bi³⁺ in BiVO₄, leading to lattice distortion and thus promoting carrier separation. The anchored Cu-RuO₂ co-catalyst can both form a lattice-matched structure with BiVO₄, thereby reducing the interfacial transfer resistance and accelerating the kinetics of the water oxidation reaction. Under the synergistic effect of the dual modification, the PEC water oxidation performance of BiVO₄ photoanodes is significantly improved.

Abstract

The poor carrier separation capability and sluggish water oxidation reaction kinetics are two critical factors that impact the photoelectrochemical (PEC) water splitting performance of the bismuth vanadate (BiVO₄) photoanode. Previous studies have demonstrated that doping with rare-earth elements to induce lattice distortions and loading oxygen evolution reaction (OER) co-catalysts are effective strategies for enhancing carrier separation capabilities and accelerating the kinetics of the water oxidation reaction. Herein, Cu²⁺-doped RuO₂ (Cu-RuO₂) particles are anchored onto rare earth element Thulium (Tm)-doped BiVO₄ (Tm-BiVO₄) photoanode substrates, constructing an integrated Cu-RuO₂-Tm-BiVO₄ photoanode. The newly integrated photoanode not only achieves a photocurrent density of 5.3 mA cm⁻² at 1.23 V versus a reversible hydrogen electrode (vs RHE), but also exhibits exceptional stability. A series of detailed physical and chemical characterizations as well as density-functional theory (DFT) calculations demonstrate that Tm doping induces lattice distortion in BiVO₄, enhancing the internal electric field and thereby facilitating carrier separation. Moreover, the anchored Cu-RuO₂ particles not only lattice-match with the Tm-BiVO₄ photoanode, reducing interfacial transfer resistance, but also expedite the kinetics of the water oxidation reaction. The profound significance of this work is that it offers a reference for the future design and fabrication of novel integrated photoanodes.

Nature, Published online: 10 July 2024; doi:10.1038/s41586-024-07698-1

An atlas of tumour vasculature shows that tumour angiogenesis is initiated from venous endothelial cells and extended towards arterial endothelial cells.