Digital holographic microscopy enables the 3D reconstruction of volumetric samples from a single-snapshot hologram.However,unlike a conventional bright-field microscopy image,the quality of holographic reconstructions...Digital holographic microscopy enables the 3D reconstruction of volumetric samples from a single-snapshot hologram.However,unlike a conventional bright-field microscopy image,the quality of holographic reconstructions is compromised by interference fringes as a result of twin images and out-of-plane objects.Here,we demonstrate that cross-modality deep learning using a generative adversarial network(GAN)can endow holographic images of a sample volume with bright-field microscopy contrast,combining the volumetric imaging capability of holography with the speckle-and artifact-free image contrast of incoherent bright-field microscopy.We illustrate the performance of this“bright-field holography”method through the snapshot imaging of bioaerosols distributed in 3D,matching the artifact-free image contrast and axial sectioning performance of a high-NA bright-field microscope.This data-driven deep-learning-based imaging method bridges the contrast gap between coherent and incoherent imaging,and enables the snapshot 3D imaging of objects with bright-field contrast from a single hologram,benefiting from the wave-propagation framework of holography.展开更多
Development of tools for targeted modifications of specific DNA sequences in plants is of great importance to basic plant biology research as well as crop improvement.The ability to cut DNA at specific locations in th...Development of tools for targeted modifications of specific DNA sequences in plants is of great importance to basic plant biology research as well as crop improvement.The ability to cut DNA at specific locations in the genome to generate doublestrand breaks（DSBs）in vivo is a prerequisite for any genome editing efforts.展开更多
Photonic bound states in the continuum(BICs)have recently been studied in various systems and have found wide applications in sensors,lasers,and filters.Applying BICs in photonic integrated circuits enables low-loss l...Photonic bound states in the continuum(BICs)have recently been studied in various systems and have found wide applications in sensors,lasers,and filters.Applying BICs in photonic integrated circuits enables low-loss light guidance and routing in low-refractive-index waveguides on high-refractive-index substrates,which opens a new avenue for integrated photonics with functional single-crystal materials.Here,we demonstrate high-quality integrated lithium niobate microcavities inside which the photonic BIC modes circulate and further modulate these BIC modes acoustooptically by using piezoelectrically actuated surface acoustic waves at microwave frequencies.With a high acoustooptic modulation frequency,the acousto-optic coupling is well situated in the resolved-sideband regime.This leads to coherent coupling between microwave and optical photons,which is exhibited by the observed electro-acoustooptically induced transparency and absorption.Therefore,our devices serve as a paradigm for manipulating and controlling photonic BICs on a chip,which will enable many other applications of photonic BICs in the areas of microwave photonics and quantum information processing.展开更多
Leaf functional traits are adaptations that enable plants to live under various environmental conditions. This study aims to determine the differences in leaf functional traits among plants grouped by growth habit, le...Leaf functional traits are adaptations that enable plants to live under various environmental conditions. This study aims to determine the differences in leaf functional traits among plants grouped by growth habit, leaf life span,leaf lifestyle, leaf form, and origin. Specific leaf area（SLA） of perennial or evergreen species was lower than that of annual or deciduous species because longer-lived leaves of perennial or evergreen species require more investment in structural integrity and/or defense against disturbances, especially with any resource constraint. SLA of large individuals was lower than that of small individuals. The low SLA in large individuals can improve their response to changing light and water conditions because increasing plant height is advantageous for light competition, but it can also impose a cost in terms of structural support and water transport. Petioles of plants with compound leaves were significantly longer than those of simple leaves because branching is expensive in terms of gaining height. SLA of plants increased with increasing invasiveness accordingly, and SLA of invasive plants was higher than that of their native congeners because invasive plants should invest more biomass on leaf growth rather than leaf structures per unit area to achieve a higher growth rate.Overall, variation in leaf functional traits among different groups may play an adaptive role in the successful survival of plants under diverse environments because leaf functional traits can lead to pronounced effects on leaf function,especially the acquisition and use of light. Plant species with different growth and leaf traits balance resource acquisition and leaf construction to minimize trade-offs and achieve fitness advantages in their natural habitat.展开更多
Being capable of sensing broadband infrared(IR)light is vitally important for wide-ranging applications from fundamental science to industrial purposes.Two-dimensional(2D)topological semimetals are being extensively e...Being capable of sensing broadband infrared(IR)light is vitally important for wide-ranging applications from fundamental science to industrial purposes.Two-dimensional(2D)topological semimetals are being extensively explored for broadband IR detection due to their gapless electronic structure and the linear energy dispersion relation.However,the low charge separation efficiency,high noise level,and on-chip integration difficulty of these semimetals significantly hinder their further technological applications.Here,we demonstrate a facile thermal-assisted tellurization route for the van der Waals(vdW)growth of wafer-scale phase-controlled 2D MoTe_(2)layers.Importantly,the type-ⅡWeyl semimetal 1T'-MoTe_(2)features a unique orthorhombic lattice structure with a broken inversion symmetry,which ensures efficient carrier transportation and thus reduces the carrier recombination.This characteristic is a key merit for the well-designed 1T'-MoTe_(2)/Si vertical Schottky junction photodetector to achieve excellent performance with an ultrabroadband detection range of up to 10.6μm and a large room temperature specific detectivity of over 108 Jones in the mid-infrared(MIR)range.Moreover,the large-area synthesis of 2D MoTe_(2)layers enables the demonstration of high-resolution uncooled MIR imaging capability by using an integrated device array.This work provides a new approach to assembling uncooled IR photodetectors based on 2D materials.展开更多
Flexible and stretchable tactile sensors that are printable,nonplanar,and dynamically morphing are emerging to enable proprioceptive interactions with the unstructured surrounding environment.Owing to its varied range...Flexible and stretchable tactile sensors that are printable,nonplanar,and dynamically morphing are emerging to enable proprioceptive interactions with the unstructured surrounding environment.Owing to its varied range of applications in the field of wearable electronics,soft robotics,human-machine interaction,and biomedical devices,it is required of these sensors to be flexible and stretchable conforming to the arbitrary surfaces of their stiff counterparts.The challenges in maintaining the fundamental features of these sensors,such as flexibility,sensitivity,repeatability,linearity,and durability,are tackled by the progress in the fabrication techniques and customization of the material properties.This review is aimed at summarizing the recent progress of rapid prototyping of sensors,printable material preparation,required printing properties,flexible and stretchable mechanisms,and promising applications and highlights challenges and opportunities in this research paradigm.展开更多
Polarization optics plays a pivotal role in diffractive,refractive,and emerging flat optics,and has been widely employed in contemporary optical industries and daily life.Advanced polarization manipulation leads to ro...Polarization optics plays a pivotal role in diffractive,refractive,and emerging flat optics,and has been widely employed in contemporary optical industries and daily life.Advanced polarization manipulation leads to robust control of the polarization direction of light.Nevertheless,polarization control has been studied largely independent of the phase or intensity of light.Here,we propose and experimentally validate a Malus-metasurface-assisted paradigm to enable simultaneous and independent control of the intensity and phase properties of light simply by polarization modulation.The orientation degeneracy of the classical Malus’s law implies a new degree of freedom and enables us to establish a one-to-many mapping strategy for designing anisotropic plasmonic nanostructures to engineer the Pancharatnam–Berry phase profile,while keeping the continuous intensity modulation unchanged.The proposed Malus metadevice can thus generate a near-field greyscale pattern,and project an independent far-field holographic image using an ultrathin and single-sized metasurface.This concept opens up distinct dimensions for conventional polarization optics,which allows one to merge the functionality of phase manipulation into an amplitudemanipulation-assisted optical component to form a multifunctional nano-optical device without increasing the complexity of the nanostructures.It can empower advanced applications in information multiplexing and encryption,anti-counterfeiting,dual-channel display for virtual/augmented reality,and many other related fields.展开更多
Modulating basal ganglia circuitry is of great signifcance in the improvement of motor function in Parkinson’s disease(PD).Here,for the frst time,we demonstrate that noninvasive ultrasound deep brain stimulation(UDBS...Modulating basal ganglia circuitry is of great signifcance in the improvement of motor function in Parkinson’s disease(PD).Here,for the frst time,we demonstrate that noninvasive ultrasound deep brain stimulation(UDBS)of the subthalamic nucleus(STN)or the globus pallidus(GP)improves motor behavior in a subacute mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).Immunohistochemical c-Fos protein expression confrms that there is a relatively high level of c-Fos expression in the STN-UDBS and GP-UDBS group compared with sham group(both p<0.05).Furthermore,STN-UDBS or GPUDBS signifcantly increases the latency to fall in the rotarod test on day 9(p<0.05)and decreases the time spent climbing down a vertical rod in the pole test on day 12(p<0.05).Moreover,our results reveal that STN-UDBS or GP-UDBS protects the dopamine(DA)neurons from MPTP neurotoxicity by downregulating Bax(p<0.001),upregulating Bcl-2(p<0.01),blocking cytochrome c(Cyt C)release from mitochondria(p<0.05),and reducing cleaved-caspase 3 activity(p<0.01)in the ipsilateral substantia nigra(SN).Additionally,the safety of ultrasound stimulation is characterized by hematoxylin and eosin(HE)and Nissl staining;no hemorrhage or tissue damage is detected.Tese data demonstrate that UDBS enables modulation of STN or GP neural activity and leads to neuroprotection in PD mice,potentially serving as a noninvasive strategy for the clinical treatment of PD.展开更多
Electronic skin made of thin,soft,stretchable devices that can mimic the human skin and reconstruct the tactile sensation and perception offers great opportunities for prosthesis sensing,robotics controlling,and human...Electronic skin made of thin,soft,stretchable devices that can mimic the human skin and reconstruct the tactile sensation and perception offers great opportunities for prosthesis sensing,robotics controlling,and human-machine interfaces.Advanced materials and mechanics engineering of thin film devices has proven to be an efficient route to enable and enhance flexibility and stretchability of various electronic skins;however,the density of devices is still low owing to the limitation in existing fabrication techniques.Here,we report a high-throughput one-step process to fabricate large tactile sensing arrays with a sensor density of 25 sensors/cm^(2) for electronic skin,where the sensors are based on intrinsically stretchable piezoelectric lead zirconate titanate(PZT)elastomer.The PZT elastomer sensor arrays with great uniformity and passive-driven manner enable highresolution tactile sensing,simplify the data acquisition process,and lower the manufacturing cost.The high-throughput fabrication process provides a general platform for integrating intrinsically stretchable materials into large area,high device density soft electronics for the next-generation electronic skin.展开更多
Photonic sensors that are able to detect and track biochemical molecules offer powerful tools for information acquisition in applications ranging from environmental analysis to medical diagnosis.The ultimate aim of bi...Photonic sensors that are able to detect and track biochemical molecules offer powerful tools for information acquisition in applications ranging from environmental analysis to medical diagnosis.The ultimate aim of biochemical sensing is to achieve both quantitative sensitivity and selectivity.As atomically thick films with remarkable optoelectronic tunability,graphene and its derived materials have shown unique potential as a chemically tunable platform for sensing,thus enabling significant performance enhancement,versatile functionalization and flexible device integration.Here,we demonstrate a partially reduced graphene oxide(prGO)inner-coated and fiber-calibrated Fabry-Perot dye resonator for biochemical detection.Versatile functionalization in the prGO film enables the intracavity fluorescent resonance energy transfer(FRET)to be chemically selective in the visible band.Moreover,by measuring the intermode interference via noise canceled beat notes and locked-in heterodyne detection with Hz-level precision,we achieved individual molecule sensitivity for dopamine,nicotine and single-strand DNA detection.This work combines atomic-layer nanoscience and high-resolution optoelectronics,providing a way toward high-performance biochemical sensors and systems.展开更多
The limited bioavailability of plant-derived natural products with anticancer activity poses major challenges to the pharmaceutical industry.An example of this is camptothecin,a monoterpene indole alkaloid with potent...The limited bioavailability of plant-derived natural products with anticancer activity poses major challenges to the pharmaceutical industry.An example of this is camptothecin,a monoterpene indole alkaloid with potent anticancer activity that is extracted at very low concentrations from woody plants.Recently,camptothecin biosynthesis has been shown to become biotechnologically amenable in hairy-root systems of the natural producer Ophiorrhiza pumila.Here,time-course expression and metabolite analyses were performed to identify novel transcriptional regulators of camptothecin biosynthesis in O.pumila.It is shown here that camptothecin production increased over cultivation time and that the expression pattern of the WRKY transcription factor encoding gene OpWRKY2 is closely correlated with camptothecin accumulation.Overexpression of OpWRKY2 led to a more than three-fold increase in camptothecin levels.Accordingly,silencing of OpWRKY2 correlated with decreased camptothecin levels in the plant.Further detailed molecular characterization by electrophoretic mobility shift,yeast one-hybrid and dual-luciferase assays showed that OpWRKY2 directly binds and activates the central camptothecin pathway gene OpTDC.Taken together,the results of this study demonstrate that OpWRKY2 acts as a direct positive regulator of camptothecin biosynthesis.As such,a feasible strategy for the over-accumulation of camptothecin in a biotechnologically amenable system is presented.展开更多
A high concentration of the total dissolved gas（TDG） in a flow downstream high dams may cause the gas bubble disease in fishes.To better understand the spatial distribution of a supersaturated TDG,a numerical simula...A high concentration of the total dissolved gas（TDG） in a flow downstream high dams may cause the gas bubble disease in fishes.To better understand the spatial distribution of a supersaturated TDG,a numerical simulation approach for determining the TDG concentration is shown to be effective and convenient; however,the determination of the model parameters relies to a great extent on the observed field data,which are scarce but are very sensitive to the accuracy of the simulation.In this regard,determining the source parameter in the TDG transport equation is the primary concern of this paper.Observed field data from six different spillways in China are used to calibrate the source parameter.A relationship between the source parameter and the hydrodynamic characteristics is established.The inclusion of this relationship in the predictive relationship will enable an accurate and rapid estimation of the source parameter and may help in developing mitigation measures for the TDG supersaturation downstream the spillways.展开更多
Reconfigurable systems complement the existing efforts of miniaturizing integrated circuits to provide a new direction for the development of future electronics.Such systems can integrate low dimensional materials and...Reconfigurable systems complement the existing efforts of miniaturizing integrated circuits to provide a new direction for the development of future electronics.Such systems can integrate low dimensional materials and metamaterials to enable functional transformation from the deformation to changes in multiple physical properties,including mechanical,electric,optical,and thermal.Capable of overcoming the mismatch in geometries and forms between rigid electronics and soft tissues,bio-integrated electronics enabled by reconfigurable systems can provide continuous monitoring of physiological signals.The new opportunities also extend beyond to human-computer interfaces,diagnostic/therapeutic platforms,and soft robotics.In the development of these systems,biomimicry has been a long lasting inspiration for the novel yet simple designs and technological innovations.As interdisciplinary research becomes evident in such development,collaboration across scientists and physicians from diverse backgrounds would be highly encouraged to tackle grand challenges in this field.展开更多
A single-step printable platform for ultraviolet(UV)metasurfaces is introduced to overcome both the scarcity of low-loss UV materials and manufacturing limitations of high cost and low throughput.By dispersing zirconi...A single-step printable platform for ultraviolet(UV)metasurfaces is introduced to overcome both the scarcity of low-loss UV materials and manufacturing limitations of high cost and low throughput.By dispersing zirconium dioxide(ZrO_(2))nanoparticles in a UV-curable resin,ZrO_(2)nanoparticle-embedded-resin(nano-PER)is developed as a printable material which has a high refractive index and low extinction coefficient from near-UV to deep-UV.In ZrO_(2)nano-PER,the UV-curable resin enables direct pattern transfer and ZrO_(2)nanoparticles increase the refractive index of the composite while maintaining a large bandgap.With this concept,UV metasurfaces can be fabricated in a single step by nanoimprint lithography.As a proof of concept,UV metaholograms operating in near-UV and deep-UV are experimentally demonstrated with vivid and clear holographic images.The proposed method enables repeat and rapid manufacturing of UV metasurfaces,and thus will bring UV metasurfaces more close to real life.展开更多
Over the past 60 years,the semiconductor industry has been the core driver for the development of information technology,contributing to the birth of integrated circuits,Internet,artificial intelligence,and Internet o...Over the past 60 years,the semiconductor industry has been the core driver for the development of information technology,contributing to the birth of integrated circuits,Internet,artificial intelligence,and Internet of Things.Semiconductor technology has been evolving in structure and material with co-optimization of performance–power–area–cost until the state-of-the-art sub-5-nm node.Two-dimensional(2D)semiconductors are recognized by the industry and academia as a hopeful solution to break through the quantum confinement for the future technology nodes.In the recent 10 years,the key issues on 2D semiconductors regarding material,processing,and integration have been overcome in sequence,making 2D semiconductors already on the verge of application.In this paper,the evolution of transistors is reviewed by outlining the potential of 2D semiconductors as a technological option beyond the scaled metal oxide semiconductor field-effect transistors.We mainly focus on the optimization strategies of mobility(μ),equivalent oxide thickness(EOT),and contact resistance(RC),which enables high ON current(Ion)with reduced driving voltage(Vdd).Finally,we prospect the semiconductor technology roadmap by summarizing the technological development of 2D semiconductors over the past decade.展开更多
Three-dimensional(3D)direct laser writing(DLW)based on two-photon polymerisation(TPP)is an advanced technology for fabricating precise 3D hydrogel micro-and nanostructures for applications in biomedical engineering.Pa...Three-dimensional(3D)direct laser writing(DLW)based on two-photon polymerisation(TPP)is an advanced technology for fabricating precise 3D hydrogel micro-and nanostructures for applications in biomedical engineering.Particularly,the use of visible lasers for the 3D DLW of hydrogels is advantageous because it enables high fabrication resolution and promotes wound healing.Polyethylene glycol diacrylate(PEGda)has been widely used in TPP fabrication owing to its high biocompatibility.However,the high laser power required in the 3D DLW of PEGda microstructures using a visible laser in a high-water-content environment limits its applications to only those below the biological laser power safety level.In this study,a formula for a TPP hydrogel based on 2-hydroxy-2-methylpropiophenone(HMPP)and PEGda was developed for the fabrication of 3D DLW microstructures at a low threshold power(0.1 nJ per laser pulse at a writing speed of 10μm·s^(−1))in a high-water-content environment(up to 79%)using a green laser beam(535 nm).This formula enables the fabrication of microstructures with micrometre fabrication resolution and high mechanical strength(megapascal level)and is suitable for the fabrication of waterresponsive,shape-changing microstructures.These results will promote the utilisation of low-power 3D DLW for fabricating hydrogel microstructures using visible lasers in high-water-content environments.展开更多
The carbon cycle is important for maintaining a stable climate and carbon balance on Earth. Renewable-electricitydriven upcycling of carbon dioxide (CO_(2)) into value-added multi-carbon molecules is a potentially sus...The carbon cycle is important for maintaining a stable climate and carbon balance on Earth. Renewable-electricitydriven upcycling of carbon dioxide (CO_(2)) into value-added multi-carbon molecules is a potentially sustainable way to alleviate greenhouse gas emission and enable production of various chemicals and fuels.展开更多
基金The Ozcan Group at UCLA acknowledges the support of the Koç Group,the National Science Foundation(PATHS-UP ERC)the Howard Hughes Medical Institute.Y.W.also acknowledges the support of the SPIE John Kiel Scholarship.
文摘Digital holographic microscopy enables the 3D reconstruction of volumetric samples from a single-snapshot hologram.However,unlike a conventional bright-field microscopy image,the quality of holographic reconstructions is compromised by interference fringes as a result of twin images and out-of-plane objects.Here,we demonstrate that cross-modality deep learning using a generative adversarial network(GAN)can endow holographic images of a sample volume with bright-field microscopy contrast,combining the volumetric imaging capability of holography with the speckle-and artifact-free image contrast of incoherent bright-field microscopy.We illustrate the performance of this“bright-field holography”method through the snapshot imaging of bioaerosols distributed in 3D,matching the artifact-free image contrast and axial sectioning performance of a high-NA bright-field microscope.This data-driven deep-learning-based imaging method bridges the contrast gap between coherent and incoherent imaging,and enables the snapshot 3D imaging of objects with bright-field contrast from a single hologram,benefiting from the wave-propagation framework of holography.
基金supported by a National Transgenic Science and Technology Program (2016ZX08010002)to R.W.a startup fund from the Huazhong Agricultural University
文摘Development of tools for targeted modifications of specific DNA sequences in plants is of great importance to basic plant biology research as well as crop improvement.The ability to cut DNA at specific locations in the genome to generate doublestrand breaks（DSBs）in vivo is a prerequisite for any genome editing efforts.
基金supported by the Early Career Scheme(24208915)the General Research Fund(14208717,14206318)sponsored by the Research Grants Council of Hong Kong+1 种基金by the NSFC/RGC Joint Research Scheme(N_CUHK415/15)sponsored by the Research Grants Council of Hong Kongthe National Natural Science Foundation of China.
文摘Photonic bound states in the continuum(BICs)have recently been studied in various systems and have found wide applications in sensors,lasers,and filters.Applying BICs in photonic integrated circuits enables low-loss light guidance and routing in low-refractive-index waveguides on high-refractive-index substrates,which opens a new avenue for integrated photonics with functional single-crystal materials.Here,we demonstrate high-quality integrated lithium niobate microcavities inside which the photonic BIC modes circulate and further modulate these BIC modes acoustooptically by using piezoelectrically actuated surface acoustic waves at microwave frequencies.With a high acoustooptic modulation frequency,the acousto-optic coupling is well situated in the resolved-sideband regime.This leads to coherent coupling between microwave and optical photons,which is exhibited by the observed electro-acoustooptically induced transparency and absorption.Therefore,our devices serve as a paradigm for manipulating and controlling photonic BICs on a chip,which will enable many other applications of photonic BICs in the areas of microwave photonics and quantum information processing.
基金supported by the National Natural Science Foundation of China(31300343)Natural Science Foundation of Jiangsu Province,China(BK20130500)Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,Research Foundation for Advanced Talents,Jiangsu University(12JDG086)
文摘Leaf functional traits are adaptations that enable plants to live under various environmental conditions. This study aims to determine the differences in leaf functional traits among plants grouped by growth habit, leaf life span,leaf lifestyle, leaf form, and origin. Specific leaf area（SLA） of perennial or evergreen species was lower than that of annual or deciduous species because longer-lived leaves of perennial or evergreen species require more investment in structural integrity and/or defense against disturbances, especially with any resource constraint. SLA of large individuals was lower than that of small individuals. The low SLA in large individuals can improve their response to changing light and water conditions because increasing plant height is advantageous for light competition, but it can also impose a cost in terms of structural support and water transport. Petioles of plants with compound leaves were significantly longer than those of simple leaves because branching is expensive in terms of gaining height. SLA of plants increased with increasing invasiveness accordingly, and SLA of invasive plants was higher than that of their native congeners because invasive plants should invest more biomass on leaf growth rather than leaf structures per unit area to achieve a higher growth rate.Overall, variation in leaf functional traits among different groups may play an adaptive role in the successful survival of plants under diverse environments because leaf functional traits can lead to pronounced effects on leaf function,especially the acquisition and use of light. Plant species with different growth and leaf traits balance resource acquisition and leaf construction to minimize trade-offs and achieve fitness advantages in their natural habitat.
基金supported by the National Natural Science Foundation of China(Nos.U2004165,U22A20138,52225303,91833303,and 12174349)Natural Science Foundation of Henan Province,China(No.202300410376)Henan provincial key science and technology research projects(No.212102210130).
文摘Being capable of sensing broadband infrared(IR)light is vitally important for wide-ranging applications from fundamental science to industrial purposes.Two-dimensional(2D)topological semimetals are being extensively explored for broadband IR detection due to their gapless electronic structure and the linear energy dispersion relation.However,the low charge separation efficiency,high noise level,and on-chip integration difficulty of these semimetals significantly hinder their further technological applications.Here,we demonstrate a facile thermal-assisted tellurization route for the van der Waals(vdW)growth of wafer-scale phase-controlled 2D MoTe_(2)layers.Importantly,the type-ⅡWeyl semimetal 1T'-MoTe_(2)features a unique orthorhombic lattice structure with a broken inversion symmetry,which ensures efficient carrier transportation and thus reduces the carrier recombination.This characteristic is a key merit for the well-designed 1T'-MoTe_(2)/Si vertical Schottky junction photodetector to achieve excellent performance with an ultrabroadband detection range of up to 10.6μm and a large room temperature specific detectivity of over 108 Jones in the mid-infrared(MIR)range.Moreover,the large-area synthesis of 2D MoTe_(2)layers enables the demonstration of high-resolution uncooled MIR imaging capability by using an integrated device array.This work provides a new approach to assembling uncooled IR photodetectors based on 2D materials.
基金This research is supported by the Singapore Academic Research Fund under Grant R-397-000-297-114.
文摘Flexible and stretchable tactile sensors that are printable,nonplanar,and dynamically morphing are emerging to enable proprioceptive interactions with the unstructured surrounding environment.Owing to its varied range of applications in the field of wearable electronics,soft robotics,human-machine interaction,and biomedical devices,it is required of these sensors to be flexible and stretchable conforming to the arbitrary surfaces of their stiff counterparts.The challenges in maintaining the fundamental features of these sensors,such as flexibility,sensitivity,repeatability,linearity,and durability,are tackled by the progress in the fabrication techniques and customization of the material properties.This review is aimed at summarizing the recent progress of rapid prototyping of sensors,printable material preparation,required printing properties,flexible and stretchable mechanisms,and promising applications and highlights challenges and opportunities in this research paradigm.
基金the support from the MOST 2017YFA0205800the funding provided by the National Natural Science Foundation of China(Nos.91950110,11774273,11904267,61805184,and 11674256)+2 种基金the financial support from the Postdoctoral Innovation Talent Support Program of China(BX20180221)the China Postdoctoral Science Foundation(2019M652688)the financial support from the National Research Foundation,Prime Minister’s Office,Singapore under its Competitive Research Program(CRP award NRF CRP15-2015-03).
文摘Polarization optics plays a pivotal role in diffractive,refractive,and emerging flat optics,and has been widely employed in contemporary optical industries and daily life.Advanced polarization manipulation leads to robust control of the polarization direction of light.Nevertheless,polarization control has been studied largely independent of the phase or intensity of light.Here,we propose and experimentally validate a Malus-metasurface-assisted paradigm to enable simultaneous and independent control of the intensity and phase properties of light simply by polarization modulation.The orientation degeneracy of the classical Malus’s law implies a new degree of freedom and enables us to establish a one-to-many mapping strategy for designing anisotropic plasmonic nanostructures to engineer the Pancharatnam–Berry phase profile,while keeping the continuous intensity modulation unchanged.The proposed Malus metadevice can thus generate a near-field greyscale pattern,and project an independent far-field holographic image using an ultrathin and single-sized metasurface.This concept opens up distinct dimensions for conventional polarization optics,which allows one to merge the functionality of phase manipulation into an amplitudemanipulation-assisted optical component to form a multifunctional nano-optical device without increasing the complexity of the nanostructures.It can empower advanced applications in information multiplexing and encryption,anti-counterfeiting,dual-channel display for virtual/augmented reality,and many other related fields.
基金We wish to thank Dr.Jun Jia(Capital Medical University)for assisting us with experimental design and Dr.Yunhui Liu(Shenzhen Institutes of Advanced Technology)for technical guidance.This work was supported by the National Natural Science Foundation of China(Grants nos.81527901,11534013,11774371,11574341,11674347,and 11874381)Natural Science Foundation of Guangdong Province(2017B030306011)Youth Innovation Promotion Association CAS(2018393).
文摘Modulating basal ganglia circuitry is of great signifcance in the improvement of motor function in Parkinson’s disease(PD).Here,for the frst time,we demonstrate that noninvasive ultrasound deep brain stimulation(UDBS)of the subthalamic nucleus(STN)or the globus pallidus(GP)improves motor behavior in a subacute mouse model of PD induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP).Immunohistochemical c-Fos protein expression confrms that there is a relatively high level of c-Fos expression in the STN-UDBS and GP-UDBS group compared with sham group(both p<0.05).Furthermore,STN-UDBS or GPUDBS signifcantly increases the latency to fall in the rotarod test on day 9(p<0.05)and decreases the time spent climbing down a vertical rod in the pole test on day 12(p<0.05).Moreover,our results reveal that STN-UDBS or GP-UDBS protects the dopamine(DA)neurons from MPTP neurotoxicity by downregulating Bax(p<0.001),upregulating Bcl-2(p<0.01),blocking cytochrome c(Cyt C)release from mitochondria(p<0.05),and reducing cleaved-caspase 3 activity(p<0.01)in the ipsilateral substantia nigra(SN).Additionally,the safety of ultrasound stimulation is characterized by hematoxylin and eosin(HE)and Nissl staining;no hemorrhage or tissue damage is detected.Tese data demonstrate that UDBS enables modulation of STN or GP neural activity and leads to neuroprotection in PD mice,potentially serving as a noninvasive strategy for the clinical treatment of PD.
基金This work was supported by the City University of Hong Kong(Grant Nos.9610423,9667199)Research Grants Council of the Hong Kong Special Administrative Region(Grant No.21210820)+2 种基金Department of Science and Technology of Sichuan Province(Grant No.2020YFH0181)Z.X.acknowledges the support from the National Natural Science Foundation of China(Grant No.12072057)Fundamental Research Funds for the Central Universities(Grant No.DUT20RC(3)032).
文摘Electronic skin made of thin,soft,stretchable devices that can mimic the human skin and reconstruct the tactile sensation and perception offers great opportunities for prosthesis sensing,robotics controlling,and human-machine interfaces.Advanced materials and mechanics engineering of thin film devices has proven to be an efficient route to enable and enhance flexibility and stretchability of various electronic skins;however,the density of devices is still low owing to the limitation in existing fabrication techniques.Here,we report a high-throughput one-step process to fabricate large tactile sensing arrays with a sensor density of 25 sensors/cm^(2) for electronic skin,where the sensors are based on intrinsically stretchable piezoelectric lead zirconate titanate(PZT)elastomer.The PZT elastomer sensor arrays with great uniformity and passive-driven manner enable highresolution tactile sensing,simplify the data acquisition process,and lower the manufacturing cost.The high-throughput fabrication process provides a general platform for integrating intrinsically stretchable materials into large area,high device density soft electronics for the next-generation electronic skin.
基金supported by the Ingeer International Certification Assessment Co.Ltd.(ICAS)support from the National Science Foundation of China(61705032,61975025)+1 种基金the 111 Project(B14039)the National Science Foundation(EFRI-1741707).
文摘Photonic sensors that are able to detect and track biochemical molecules offer powerful tools for information acquisition in applications ranging from environmental analysis to medical diagnosis.The ultimate aim of biochemical sensing is to achieve both quantitative sensitivity and selectivity.As atomically thick films with remarkable optoelectronic tunability,graphene and its derived materials have shown unique potential as a chemically tunable platform for sensing,thus enabling significant performance enhancement,versatile functionalization and flexible device integration.Here,we demonstrate a partially reduced graphene oxide(prGO)inner-coated and fiber-calibrated Fabry-Perot dye resonator for biochemical detection.Versatile functionalization in the prGO film enables the intracavity fluorescent resonance energy transfer(FRET)to be chemically selective in the visible band.Moreover,by measuring the intermode interference via noise canceled beat notes and locked-in heterodyne detection with Hz-level precision,we achieved individual molecule sensitivity for dopamine,nicotine and single-strand DNA detection.This work combines atomic-layer nanoscience and high-resolution optoelectronics,providing a way toward high-performance biochemical sensors and systems.
基金the National Key Research and Development Program of China(2018YFC1706203)National Natural Science Foundation of China(31571735,82073963,81522049,82003889)+3 种基金Zhejiang Provincial Ten Thousands Program for Leading Talents of Science and Technology Innovation(2018R52050)Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents,Shanghai Science and Technology Committee Project(17JC1404300)Zhejiang Provincial Natural Science Foundation of China(LY20H280008,LQ21H280004)Zhejiang Chinese Medical University Research Foundation(2020ZR15).
文摘The limited bioavailability of plant-derived natural products with anticancer activity poses major challenges to the pharmaceutical industry.An example of this is camptothecin,a monoterpene indole alkaloid with potent anticancer activity that is extracted at very low concentrations from woody plants.Recently,camptothecin biosynthesis has been shown to become biotechnologically amenable in hairy-root systems of the natural producer Ophiorrhiza pumila.Here,time-course expression and metabolite analyses were performed to identify novel transcriptional regulators of camptothecin biosynthesis in O.pumila.It is shown here that camptothecin production increased over cultivation time and that the expression pattern of the WRKY transcription factor encoding gene OpWRKY2 is closely correlated with camptothecin accumulation.Overexpression of OpWRKY2 led to a more than three-fold increase in camptothecin levels.Accordingly,silencing of OpWRKY2 correlated with decreased camptothecin levels in the plant.Further detailed molecular characterization by electrophoretic mobility shift,yeast one-hybrid and dual-luciferase assays showed that OpWRKY2 directly binds and activates the central camptothecin pathway gene OpTDC.Taken together,the results of this study demonstrate that OpWRKY2 acts as a direct positive regulator of camptothecin biosynthesis.As such,a feasible strategy for the over-accumulation of camptothecin in a biotechnologically amenable system is presented.
基金supported by the National Natural Science Foun-dation of China(Grant Nos.51279115,51179111)
文摘A high concentration of the total dissolved gas（TDG） in a flow downstream high dams may cause the gas bubble disease in fishes.To better understand the spatial distribution of a supersaturated TDG,a numerical simulation approach for determining the TDG concentration is shown to be effective and convenient; however,the determination of the model parameters relies to a great extent on the observed field data,which are scarce but are very sensitive to the accuracy of the simulation.In this regard,determining the source parameter in the TDG transport equation is the primary concern of this paper.Observed field data from six different spillways in China are used to calibrate the source parameter.A relationship between the source parameter and the hydrodynamic characteristics is established.The inclusion of this relationship in the predictive relationship will enable an accurate and rapid estimation of the source parameter and may help in developing mitigation measures for the TDG supersaturation downstream the spillways.
基金the start-up fund provided by the Engineering Science and Mechanics Department,College of Engineering,and Materials Research Institute at The Pennsylvania State UniversityNSFC(Grant Nos.11572161 and 11272260)+1 种基金ASME Haythornthwaite Foundation Research Initiation GrantDorothy Quiggle Career Development Professorship in Engineering at Penn State.
文摘Reconfigurable systems complement the existing efforts of miniaturizing integrated circuits to provide a new direction for the development of future electronics.Such systems can integrate low dimensional materials and metamaterials to enable functional transformation from the deformation to changes in multiple physical properties,including mechanical,electric,optical,and thermal.Capable of overcoming the mismatch in geometries and forms between rigid electronics and soft tissues,bio-integrated electronics enabled by reconfigurable systems can provide continuous monitoring of physiological signals.The new opportunities also extend beyond to human-computer interfaces,diagnostic/therapeutic platforms,and soft robotics.In the development of these systems,biomimicry has been a long lasting inspiration for the novel yet simple designs and technological innovations.As interdisciplinary research becomes evident in such development,collaboration across scientists and physicians from diverse backgrounds would be highly encouraged to tackle grand challenges in this field.
基金supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCO,a university R&D program funded by Samsung Electronics,and the National Research Foundation(NRF)grants(NRF-2022M3C1A3081312,NRF-2022M3H4A1A02074314,NRF-2021K1A3A1A17086079,NRF-2021K2A9A2A15000174,CAMM-2019M3A6B3030637,NRF-2019R1A5A8080290)funded by the Ministry of Science and ICT(MSIT)of the Korean government.
文摘A single-step printable platform for ultraviolet(UV)metasurfaces is introduced to overcome both the scarcity of low-loss UV materials and manufacturing limitations of high cost and low throughput.By dispersing zirconium dioxide(ZrO_(2))nanoparticles in a UV-curable resin,ZrO_(2)nanoparticle-embedded-resin(nano-PER)is developed as a printable material which has a high refractive index and low extinction coefficient from near-UV to deep-UV.In ZrO_(2)nano-PER,the UV-curable resin enables direct pattern transfer and ZrO_(2)nanoparticles increase the refractive index of the composite while maintaining a large bandgap.With this concept,UV metasurfaces can be fabricated in a single step by nanoimprint lithography.As a proof of concept,UV metaholograms operating in near-UV and deep-UV are experimentally demonstrated with vivid and clear holographic images.The proposed method enables repeat and rapid manufacturing of UV metasurfaces,and thus will bring UV metasurfaces more close to real life.
基金the National Natural Science Foundation of China(Grant Numbers 62204124,96964202,62204130,52105369,and 61974070)the Natural Science Foundation of Jiangsu Province(Grant Numbers BK20220397,BK20180759,BK20190725,BK20180759,and BK20200746)+2 种基金the Startup Foundation of Nanjing University of Posts and Telecommunications(Grant Numbers NY220114,NY220066,NY219139,NY218149,and NY220077)Guangdong Greater Bay Area Institute of Integrated Circuit and System(Grant Number 2021B0101280002)Guangzhou City Research and Development Program in Key Field(Grant Number 20210302001)。
文摘Over the past 60 years,the semiconductor industry has been the core driver for the development of information technology,contributing to the birth of integrated circuits,Internet,artificial intelligence,and Internet of Things.Semiconductor technology has been evolving in structure and material with co-optimization of performance–power–area–cost until the state-of-the-art sub-5-nm node.Two-dimensional(2D)semiconductors are recognized by the industry and academia as a hopeful solution to break through the quantum confinement for the future technology nodes.In the recent 10 years,the key issues on 2D semiconductors regarding material,processing,and integration have been overcome in sequence,making 2D semiconductors already on the verge of application.In this paper,the evolution of transistors is reviewed by outlining the potential of 2D semiconductors as a technological option beyond the scaled metal oxide semiconductor field-effect transistors.We mainly focus on the optimization strategies of mobility(μ),equivalent oxide thickness(EOT),and contact resistance(RC),which enables high ON current(Ion)with reduced driving voltage(Vdd).Finally,we prospect the semiconductor technology roadmap by summarizing the technological development of 2D semiconductors over the past decade.
基金support from the Zhangjiang National Innovation Demonstration Zone(ZJ2019-ZD-005)support from the China Postdoctoral Science Foundation(BX20180061 and 2018M642145).
文摘Three-dimensional(3D)direct laser writing(DLW)based on two-photon polymerisation(TPP)is an advanced technology for fabricating precise 3D hydrogel micro-and nanostructures for applications in biomedical engineering.Particularly,the use of visible lasers for the 3D DLW of hydrogels is advantageous because it enables high fabrication resolution and promotes wound healing.Polyethylene glycol diacrylate(PEGda)has been widely used in TPP fabrication owing to its high biocompatibility.However,the high laser power required in the 3D DLW of PEGda microstructures using a visible laser in a high-water-content environment limits its applications to only those below the biological laser power safety level.In this study,a formula for a TPP hydrogel based on 2-hydroxy-2-methylpropiophenone(HMPP)and PEGda was developed for the fabrication of 3D DLW microstructures at a low threshold power(0.1 nJ per laser pulse at a writing speed of 10μm·s^(−1))in a high-water-content environment(up to 79%)using a green laser beam(535 nm).This formula enables the fabrication of microstructures with micrometre fabrication resolution and high mechanical strength(megapascal level)and is suitable for the fabrication of waterresponsive,shape-changing microstructures.These results will promote the utilisation of low-power 3D DLW for fabricating hydrogel microstructures using visible lasers in high-water-content environments.
基金financially supported by the National Natural Science Foundation of China (Nos.50835002 and 51105102)。
文摘The carbon cycle is important for maintaining a stable climate and carbon balance on Earth. Renewable-electricitydriven upcycling of carbon dioxide (CO_(2)) into value-added multi-carbon molecules is a potentially sustainable way to alleviate greenhouse gas emission and enable production of various chemicals and fuels.
