A drug-loaded flexible substrate improves the performance of conformal cortical electrodes

Cortical electrodes are a powerful tool for the stimulation and/or recording of electrical activity in the nervous system.However,the inevitable wound caused by surgical implantation of electrodes presents bacterial infection and inflammatory reaction risks associated with foreign body exposure.Moreover,inflammation of the wound area can dramatically worsen in response to bacterial infection.These consequences can not only lead to the failure of cortical electrode implantation but also threaten the lives of patients.Herein,we prepared a hydrogel made of bacterial cellulose(BC),a flexible substrate for cortical electrodes,and further loaded antibiotic tetracycline(TC)and the anti-inflammatory drug dexamethasone(DEX)onto it.The encapsulated drugs can be released from the BC hydrogel and effectively inhibit the growth of Gram-negative and Gram-positive bacteria.Next,therapeutic cortical electrodes were developed by integrating the drug-loaded BC hydrogel and nine-channel serpentine arrays;these were used to record electrocorticography(ECoG)signals in a rat model.Due to the controlled release of TC and DEX from the BC hydrogel substrate,therapeutic cortical electrodes can alleviate or prevent symptoms associated with the bacterial infection and inflammation of brain tissue.This approach facilitates the development of drug delivery electrodes for resolving complications caused by implantable electrodes.

Surface Patterning of Metal Zinc Electrode with an In‑Region Zincophilic Interface for High‑Rate and Long‑Cycle‑Life Zinc Metal Anode

The undesirable dendrite growth induced by non-planar zinc(Zn)deposition and low Coulombic efficiency resulting from severe side reactions have been long-standing challenges for metallic Zn anodes and substantially impede the practical application of rechargeable aqueous Zn metal batteries(ZMBs).Herein,we present a strategy for achieving a high-rate and long-cycle-life Zn metal anode by patterning Zn foil surfaces and endowing a Zn-Indium(Zn-In)interface in the microchannels.The accumulation of electrons in the microchannel and the zincophilicity of the Zn-In interface promote preferential heteroepitaxial Zn deposition in the microchannel region and enhance the tolerance of the electrode at high current densities.Meanwhile,electron aggregation accelerates the dissolution of non-(002)plane Zn atoms on the array surface,thereby directing the subsequent homoepitaxial Zn deposition on the array surface.Consequently,the planar dendrite-free Zn deposition and long-term cycling stability are achieved(5,050 h at 10.0 mA cm^(−2) and 27,000 cycles at 20.0 mA cm^(−2)).Furthermore,a Zn/I_(2) full cell assembled by pairing with such an anode can maintain good stability for 3,500 cycles at 5.0 C,demonstrating the application potential of the as-prepared ZnIn anode for high-performance aqueous ZMBs.

Correction: Surface Patterning of Metal ZincElectrode with an In-Region Zincophilic Interfacefor High-Rate and Long-Cycle-Life Zinc MetalAnode

Correction to:Nano-Micro Letters(2024)16:112 https://doi.org/10.1007/s40820-024-01327-2 In the supplementary information the following corrections have been carried out:1.Institute of Energy and Climate Research,Materials Synthesis and Processing,Forschungszentrum Jülich GmbH,52425 Jülich,Germany.Corrected:Institute of Energy and Climate Research:Materials Synthesis and Processing(IEK-1),Forschungszentrum Jülich GmbH,52425 Jülich,Germany.

Flexible Healthcare Sensors for Disruptive Medical Techniques

Flexible healthcare sensors could significantly change the diagnose towards portable,wearable,remote,and timely,that will breed the revolutionary and disruptive medical technique for traditional diagnosis in clinical practice[1-4].As schematically illustrated in Fig.1a,traditional disease diagnosis always requires patients to go to hospital for diagnosis which is time-consuming and takes up a lot of medical resources.Recently,wearable health-monitoring was demonstrated by flexible healthcare sensors for telemedicine applications[5].Health-related physiological signals will be collected by flexible sensors and transmitted to hospital and database for analysis(Fig.1b).The database needs doctors input by completing the relationship between physiological signals and body conditions.The accuracy of diagnosis results mainly depends on the integrity of the database.Therefore,wearable health monitoring provides a convenient way for disease diagnosis,but the doctor s role is still crucial and irreplaceable.

Two-dimensional Conductive Metal-Organic Framework Nanowire Arrays for Highly Performed Soft Electrochemical Actuators

Fig.1(a)Schematic illustration of the fabrication of a Ni-CAT NWAs/CNF hybrid membrane by the in situ hydrothermal growth of Ni-CAT NWAs on CNF;SEM images of(b)the pristine CNF nanomembrane and(c)Ni-CAT NWAs/CNF,and(d)size distribution statistics of the diameter of Ni-CAT NWAs/CNF;schematic illustrations of(e)the fabrication procedure for the Ni-CAT NWAs/CNF-based actuator,(f)Ni-CAT NWAs/CNF electrode surfaces and Ni-CAT along the c-axis(Color codes:O,red spheres;C,gray spheres;and Ni,blue spheres);(g)actuation performance of the Ni-CAT NWAs/CNF based actuator The demand for high-performance low-voltage driven electromechanical actuators is growing because of their potential applications,such as in soft robotics,artificial muscles,biomimetic flying insects,and micro/nano-electromechanical systems[1].Among these actuators,ionic-polymer metal composite actuators(IPMCs)are promising as they are capable of large actuation deformation under low operation voltages(only a few volts),and they operate best in a humid environment[2].However,although extensive efforts have been made in past decades,developing high-capacitance electrode materials that improve the performance of IPMCs is challenging.

Carrier and magnetism engineering for monolayer SnS_(2) by high throughput first-principles calculations

Two-dimensional(2D)semiconducting tin disulfide(SnS_(2))has been widely used for optoelectronic applications.To functionalize SnS_(2) for extending its application,we investigate the stability,electronic and magnetic properties of substitutional doping by high throughput first-principles calculations.There are a lot of elements that can be doped in monolayer SnS_(2).Nonmetal in group A can introduce p-type and n-type carriers,while most metals in group A can only lead to p-type doping.Not only 3d,but also 4d and 5d transition metals in groups VB to VⅢB9 can introduce magnetism in SnS_(2),which is potentially applicable for spintronics.This study provides a comprehensive view of functionalization of SnS_(2) by substitutional doping,which will guide further experimental realization.

金属配合物的机械发光:进展与应用

摩擦发光(ML)是由机械力作用在材料上引起的发光现象。近年来,金属配合物ML材料因其独特的光学发射特性而受到广泛关注,在应力传感、防伪、结构健康监测、医疗健康、结构检测等领域有着广阔的应用前景。本文综述了近年来具有摩擦发光性质的金属配合物材料的研究进展,包括镧系金属配合物和过渡金属配合物。此外,还讨论了摩擦发光的产生机制、设计原理、光物理性质及其应用前景。本综述将为构建金属配合物摩擦发光材料以及拓展其在应力传感、结构检测等方面的应用提供启发和指导。

Inverse design and realization of an optical cavity-based displacement transducer with arbitrary responses

Optical cavity has long been critical for a variety of applications ranging from precise measurement to spectral analysis.A number of theories and methods have been successful in describing the optical response of a stratified optical cavity,while the inverse problem,especially the inverse design of a displacement sensitive cavity,remains a significant challenge due to the cost of computation and comprehensive performance requirements.This paper reports a novel inverse design methodology combining the characteristic matrix method,mixed-discrete variables optimization algorithm,and Monte Carlo method-based tolerance analysis.The material characteristics are indexed to enable the mixed-discrete variables optimization,which yields considerable speed and efficiency improvements.This method allows arbitrary response adjustment with technical feasibility and gives a glimpse into the analytical characterization of the optical response.Two entirely different light-displacement responses,including an asymmetric sawtooth-like response and a highly symmetric response,are dug out and experimentally achieved,which fully confirms the validity of the method.The compact Fabry-Perot cavities have a good balance between performance and feasibility,making them promising candidates for displacement transducers.More importantly,the proposed inverse design paves the way for a universal design of optical cavities,or even nanophotonic devices.

The Soft-Strain Effect Enabled High-Performance Flexible Pressure Sensor and Its Application in Monitoring Pulse Waves

Flexible and wearable pressure sensors attached to human skin are effective and convenient in accurate and real-time tracking of various physiological signals for disease diagnosis and health assessment.Conventional flexible pressure sensors are constructed using compressible dielectric or conductive layers,which are electrically sensitive to external mechanical stimulation.However,saturated deformation under large compression significantly restrains the detection range and sensitivity of such sensors.Here,we report a novel type of flexible pressure sensor to overcome the compression saturation of the sensing layer by softstrain ffect,enabling an utra-high sensitivity of~636 kPa^(-1) and a wide detection range from 0.1 kPa to 56 kPa.In addition,the cyclic loading-unloading test reveals the excellent stability of the sensor,which maintains its signal detection after 10.000 cycles of 10 kPa compression.The sensor is capable of monitoring arterial pulse waves from both deep tissue and distal parts,such as digital arteries and dorsal pedal arteries,which can be used for blood pressure estimation by pulse transit time at the same artery branch.

Recent advances and future perspectives of Ruddlesden–Popper perovskite oxides electrolytes for all-solid-state batteries

All-solid-state batteries equipped with solid-state electrolytes(SSEs)havegained significant interest due to their enhanced safety,energy density,andlongevity in comparison to traditional liquid organic electrolyte-based batteries.However,many SSEs,such as sulfides and hydrides,are highly sensitiveto water,limiting their practical use.As one class of important perovskites,theRuddlesden–Popper perovskite oxides(RPPOs),show great promise as SSEsdue to their exceptional stability,particularly in terms of water resistance.Inthis review,the crystal structure and synthesis methods of RPPOs SSEs are firstintroduced in brief.Subsequently,the mechanisms of ion transportation,including oxygen anions and lithium-ions,and the relevant strategies forenhancing their ionic conductivity are described in detail.Additionally,theprogress made in developing flexible RPPOs SSEs,which are critical for flexibleand wearable electronic devices,has also been summarized.Furthermore,thekey challenges and prospects for exploring and developing RPPOs SSEs in allsolid-state batteries are suggested.This review presents in detail the synthesismethods,the ion transportation mechanism,and strategies to enhance theroom temperature ionic conductivity of RPPOs SSEs,providing valuableinsights on enhancing their ionic conductivity and thus for their practicalapplication in solid-state batteries.

Recent Developments of Photodeformable Polymers:From Materials to Applications

Photodeformable polymer materials have a far influence in the fields of flexibility and intelligence.The stimulation energy is converted into mechanical energy through molecular synergy.Among kinds of photodeformable polymer materials,liquid crystalline polymer(LCP)photodeformable materials have been a hot topic in recent years.Chromophores such as azobenzene,a-cyanostilbene,and 9,10-dithiopheneanthracene have been widely used in LCP,which are helpful for designing functional molecules to increase the penetration depth of light to change physical properties.Due to the various applications of photodeformable polymer materials,there are many excellent reports in intelligent field.In this review,we have systematized LCP containing azobenzene into 3 categories depending on the degree of crosslinking liquid crystalline elastomers,liquid crystalline networks,and linear LCPs.Other structural,typical polymer materials and their applications are discussed.Current issues faced and future directions to be developed for photodeformable polymer materials are also summarized.

Review of micromachined optical accelerometers:from mg to sub-μg

Micro-Opto-Electro-Mechanical Systems(MOEMS)accelerometer is a new type of accelerometer which combines the merits of optical measurement and Micro-Electro-Mechanical Systems(MEMS)to enable high precision,small volume and anti-electromagnetic disturbance measurement of acceleration.In recent years,with the in-depth research and development of MOEMS accelerometers,the community is flourishing with the possible applications in seismic monitoring,inertial navigation,aerospace and other industrial and military fields.There have been a variety of schemes of MOEMS accelerometers,whereas the performances differ greatly due to different measurement principles and corresponding application requirements.This paper aims to address the pressing issue of the current lack of systematic review of MOEMS accelerometers.According to the optical measurement principle,we divide the MOEMS accelerometers into three categories:the geometric optics based,the wave optics based,and the new optomechanical accelerometers.Regarding the most widely studied category,the wave optics based accelerometers are further divided into four sub-categories,which is based on grating interferometric cavity,Fiber Bragg Grating(FBG),Fabry-Perot cavity,and photonic crystal,respectively.Following a brief introduction to the measurement principles,the typical performances,advantages and disadvantages as well as the potential application scenarios of all kinds of MOEMS accelerometers are discussed on the basis of typical demonstrations.This paper also presents the status and development tendency of MOEMS accelerometers to meet the ever-increasing demand for high-precision acceleration measurement.

Recent progress of flexible electronics by 2D transition metal dichalcogenides

Flexible electronics is the research field with interdisciplinary crossing and integration.It shows the promising advantages of novel device configurations,low-cost and low-power consumption due to their flexible and soft characteristics.Atomic layered two-dimensional(2D)materials especially transition metal dichalcogenides,have triggered great interest in ultra-thin 2D flexible electronic devices and optoelectronic devices because of their direct and tunable bandgaps,excellent electrical,optical,mechanical,and thermal properties.This review aims to provide the recent progress in 2D TMDs and their applications in flexible electronics.The fundamental electrical properties and mechanical properties of materials,flexible device configurations,and their performance in transistors,sensors,and photodetectors are thoroughly discussed.At last,some perspectives are given on the open challenges and prospects for 2D TMDs flexible electronic devices and new device opportunities.

Conductive Ni3(HITP)2 MOFs thin films for flexible transparent supercapacitors with high rate capability

The flexible transparent supercapacitors have been considered as one of the key energy-storage components to power the smart portable electronic devices.However,it is still a challenge to explore flexible transparent capacitive electrodes with high rate capability.Herein,conductive Ni3(HITP)2(HITP=2,3,6,7,10,11-hexaiminotriphenylene)thin films are adopted as capacitive electrodes in flexible transparent supercapacitors.The Ni3(HITP)2 electrode possesses the excellent optoelectronic property with optical transmittance(T)of 78.4%and sheet resistance(Rs)of 51.3Ωsq-1,remarkable areal capacitance(CA)of 1.63 mF cm^-2and highest scan rate up to 5000 mV s-1.The asymmetric Ni3(HITP)2//PEDOT:PSS supercapacitor(T=61%)yields a high CA of 1.06 mF cm^-2at 3μA cm-2,which maintains 77.4%as the current density increases by 50 folds.The remarkable rate capability is ascribed to the collaborative advantages of low diffusion resistance and high ion accessibility,resulting from the intrinsic conductivity,short oriented pores and large specific areas of Ni3(HITP)2 films.

Interdiscipline between optoelectronic materials and mechanical sensors:Recent advances of organic triboluminescent compounds and their applications in sensing

Triboluminescence,also as known as mechanoluminescence,is an attractive optical behavior that means the light emitted from specific organic and inorganic materials when they are subjected to external forces,such as crushing,deformation,cleaving,vibration.Inorganic triboluminescent materials show great potential for applications in sensing,such as stress sensing,damage detection.However,the triboluminescent mechanism of organic materials should be pushed further as well as their application.In this review,we summarized the history of development and possible mechanism of organic triboluminescent materials,and discussed various applications in sensing field.At the same time,inspired by the existing research progress in inorganic triboluminescent materials,we proposed the flourishing development prospects of organic triboluminescent materials in stress sensors,movement monitoring,imaging stress distribution,visualization of crack propagation,structural diagnosis,and other fields.

Hydrogel-based flexible materials for diabetes diagnosis,treatment,and management

Diabetes is a chronic metabolic disease characterized by high glucose concentration in blood.Conventional management of diabetes requires skin pricking and subcutaneous injection,causing physical pain and physiological issues to diabetic individuals.Hydrogels possess unique advantages such as lightweight,stretchability,biocompatibility,and biodegradability,offering the opportunities to be integrated as flexible devices for diabetes management.This review highlights the development of hydrogels as flexible materials for diabetes applications in glucose monitoring,insulin delivery,wound care,and cell transplantation in recent years.Challenges and prospects in the development of hydrogel-based flexible devices for personalized management of diabetes are discussed as well.

High-efficiency stretchable organic light-emitting diodes based on ultra-flexible printed embedded metal composite electrodes

Stretchable organic light-emitting diodes(OLEDs)are important components for flexible/wearable electronics.However,the efficiency of the existing stretchable OLEDs is still much lower as compared with their rigid counterparts,one of the main reasons being the lack of ideal flexible transparent electrodes.Herein,we propose and develop a printed embedded metal composite electrode(PEMCE)strategy that enables the fabrication of ultra-thin,highly flexible transparent electrodes with robust mechanical properties.With the flexible transparent electrodes serves as the anodes,flexible/stretchable white OLEDs have been successfully constructed,achieving a current efficiency of up to 77.4 cd A^(-1)and a maximum luminance of 34787 cd m^(-2).The current efficiency of the resulting stretchable OLEDs is the highest ever reported for flexible/stretchable white OLEDs,which is about 1.2 times higher than that of the reference rigid devices based on ITO/glass electrodes.The excellent optoelectronic properties of the printed embedded transparent electrodes and the light extraction effect of the Ag-mesh account for the significant increase in current efficiency.Remarkably,the electroluminescence performance still retains~83%of the original luminance even after bending the device 2000 cycles at a radii of~0.5 mm.More importantly,the device can withstand tensile strains of up to~100%,and even mechanical deformation of 90%tensile strain does not result in a significant loss of electroluminescence performance with current efficiency and luminance maintained at over 85%.The results confirm that the PEMCE strategy is effective for constructing ultra-flexible transparent electrodes,showing great promise for use in a variety of flexible/stretchable electronics.

Flexible Monitoring,Diagnosis,and Therapy by Microneedles with Versatile Materials and Devices toward Multifunction Scope

Microneedles(MNs)have drawn rising attention owing to their merits of convenience,noninvasiveness,flexible applicability,painless microchannels with boosted metabolism,and precisely tailored multifunction control.MNs can be modified to serve as novel transdermal drug delivery,which conventionally confront with the penetration barrier caused by skin stratum corneum.The micrometer-sized needles create channels through stratum corneum,enabling efficient drug delivery to the dermis for gratifying efficacy.Then,incorporating photosensitizer or photothermal agents into MNs can conduct photodynamic or photothermal therapy,respectively.Besides,health monitoring and medical detection by MN sensors can extract information from skin interstitial fluid and other biochemical/electronic signals.Here,this review discloses a novel monitoring,diagnostic,and therapeutic pattern by MNs,with elaborate discussion about the classified formation of MNs together with various applications and inherent mechanism.Hereby,multifunction development and outlook from biomedical/nanotechnology/photoelectric/devices/informatics to multidisciplinary applications are provided.Programmable intelligent MNs enable logic encoding of diverse monitoring and treatment pathways to extract signals,optimize the therapy efficacy,real-time monitoring,remote control,and drug screening,and take instant treatment.

Present and future of functionalized Cu current collectors for stabilizing lithium metal anodes

Li metal has been recognized as the most promising anode materials for next-generation high-energy-density batteries,however,the inherent issues of dendrite growth and huge volume fluctuations upon Li plating/stripping normally result in fast capacity fading and safety concerns.Functionalized Cu current collectors have so far exhibited significant regulatory effects on stabilizing Li metal anodes(LMAs),and hold a great practical potential owing to their easy fabrication,low-cost and good compatibility with the existing battery technology.In this review,a comprehensive overview of Cu-based current collectors,including planar modified Cu foil,3D architectured Cu foil and nanostructured 3D Cu substrates,for Li metal batteries is provided.Particularly,the design principles and strategies of functionalized Cu current collectors associated with their functionalities in optimizing Li plating/stripping behaviors are discussed.Finally,the critical issues where there is incomplete understanding and the future research directions of Cu current collectors in practical LMAs are also prospected.This review may shed light on the critical understanding of current collector engineering for high-energy-density Li metal batteries.

Halogenated Thermally Activated Delayed Fluorescence Materials for Efficient Scintillation

Organic scintillators,materials with the ability to exhibit luminescence when exposed to X-rays,have aroused increasing interest in recent years.However,the enhancement of radioluminescence and improving X-ray absorption of organic scintillators lie in the inherent dilemma,due to the waste of triplet excitons and weak X-ray absorption during scintillation.Here,we employ halogenated thermally activated delayed fluorescence materials to improve the triplet exciton utilization and X-ray absorption simultaneously,generating efficient scintillation with a low detection limit,which is one order of magnitude lower than the dosage for X-ray medical diagnostics.Through experimental study and theoretical calculation,we reveal the positive role of X-ray absorption,quantum yields of prompt fluorescence,and intersystem crossing in promoting the radioluminescence intensity.This finding offers an opportunity to design diverse types of organic scintillators and expands the applications of thermally activated delayed fluorescence.