Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stab...Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stability have hindered their large-scale commercial application.Herein,aflexible capacitive pressure sensor based on an interdigital electrode structure with two porous microneedle arrays(MNAs)is pro-posed.The porous substrate that constitutes the MNA is a mixed product of polydimethylsiloxane and NaHCO3.Due to its porous and interdigital structure,the maximum sensitivity(0.07 kPa-1)of a porous MNA-based pressure sensor was found to be seven times higher than that of an imporous MNA pressure sensor,and it was much greater than that of aflat pressure sensor without a porous MNA structure.Finite-element analysis showed that the interdigital MNA structure can greatly increase the strain and improve the sensitivity of the sen-sor.In addition,the porous MNA-based pressure sensor was found to have good stability over 1500 loading cycles as a result of its bilayer parylene-enhanced conductive electrode structure.Most importantly,it was found that the sensor could accurately monitor the motion of afinger,wrist joint,arm,face,abdomen,eye,and Adam’s apple.Furthermore,preliminary semantic recognition was achieved by monitoring the movement of the Adam’s apple.Finally,multiple pressure sensors were integrated into a 33 array to detect a spatial pressure distribu-×tion.Compared to the sensors reported in previous works,the interdigital electrode structure presented in this work improves sensitivity and stability by modifying the electrode layer rather than the dielectric layer.展开更多
Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the elec...Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the electrode-neural interface.Methods:A prospective observational study involving 56 pediatric patients underwent cochlear implantation with Cochlear Nucleus devices.Intraoperative polarized impedance and electrically evoked compound action potential(ECAP)threshold were recorded across all 1232 electrodes using AutoNRT software.Eight electrodes with open-or short-circuit were excluded,leaving 1,224 for analysis.Impedance values were categorized by cochlear region(basal,middle,apical),and electrodes with elevated impedance(10-20 kΩ)were analyzed for regional distribution and clinical relevance.Data were analyzed for spatial patterns and correlation with the ECAP threshold profiles.Results:A consistent basal-to-apical increase in impedance was observed(7.7±1.9,9.2±1.4,10.8±1.5 kΩ;p<0.001).Impedance and ECAP threshold were weakly correlated(ρ=-0.20,p<0.001;β=-1.26,p<0.001),with a positive association in the apical region(ρ=0.12,p=0.048).Electrodes with higher impedance(1020 kΩ)were less likely to show elevated or absent TNRT(OR=0.175,p=0.02).The impedance gradient persisted across age groups and was significantly correlated with ECAP threshold patterns.Conclusion:Intraoperative impedance monitoring reveals a strong and physiologically consistent gradient,with higher values in apical electrodes.This gradient reflects anatomical and tissue interface variations,which may offer a valuable physiological indicator for intraoperative electrode positioning and neural interface integrity.展开更多
Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applicatio...Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications.Existing schemes are limited by flexibility,biosafety,and manufacturing costs,which create large barriers for wider applications.Here,we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface,robustness of microneedles to penetrate the skin without fracture,and a simplified process to allow mass production.The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording.The normalized electrode–skin contact impedance reaches 0.98 kΩcm^(2)at 1 kHz and 1.50 kΩcm^(2)at 10 Hz,a record low value compared to previous reports and approximately 1/250 of the standard electrodes.The morphology,biosafety,and electrical/mechanical properties are fully characterized,and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized.The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording(over 8 h per night),providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.展开更多
Conducting polymers have been studied extensively. An interesting property of the conducting polymer is that the conductivity of some polymers, such as polypyrrolc, polyaniline, poly(3-methylthiophene) etc. , is affec...Conducting polymers have been studied extensively. An interesting property of the conducting polymer is that the conductivity of some polymers, such as polypyrrolc, polyaniline, poly(3-methylthiophene) etc. , is affected by the voltage applied to them. For polypyrrole, the oxidized state is an electronic conductor and the reduced state is essentially insulating. Using this property, one can fabricate the polymer-based electronic devices. Experimental results of Pickun展开更多
Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose c...Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose cell-electrode interface.To investigate intracellular electrophysiological signals with high sensitivity,electroporation was used to obtain intracellular recordings.In this study,a biosensing system based on a nanoporous electrode array(NPEA)integrating electrical perforation and signal acquisition was established to dynamically and sensitively record the intracellular potential of cardiomyocytes over a long period of time.Moreover,nanoporous electrodes can induce the protrusion of cell membranes and enhance cell-electrode interfacial coupling,thereby facilitating effective electroporation.Electrophysiological signals over the entire recording process can be quantitatively and segmentally analyzed according to the signal changes,which can equivalently reflect the dynamic evolution of the electroporated cardiomyocyte membrane.We believe that the low-cost and high-performance nanoporous biosensing platform suggested in this study can dynamically record intracellular action potential,evaluate cardiomyocyte electroporation,and provide a new strategy for investigating cardiology pharmacological science.展开更多
Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the p...Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.展开更多
Process technology of multiple cylindrical micro-pins by wire-electrical discharge machining （wire-EDM） and electrochemical etching was presented. A row of rectangular micro-columns were machined by wire-EDM and the...Process technology of multiple cylindrical micro-pins by wire-electrical discharge machining （wire-EDM） and electrochemical etching was presented. A row of rectangular micro-columns were machined by wire-EDM and then machined into cylindrical shape by electrochemical etching. However, the shape of the multiple electrodes and the consistent sizes of the electrodes row are not easy to be controlled. In the electrochemical process, the shape of the cathode electrode determines the current density distribution on the anode and so the forming of multiple electrodes. This paper proposes a finite element method （FEM） to accurately optimize the electrode profile. The microelectrodes row with uniformity diameters with size from hundreds micrometers to several decades could be fabricated, and mathematical model controlling the shape and diameter of multiple microelectrodes was provided. Furthermore, a good agreement between experimental and theoretical results was confirmed.展开更多
A global optimum location algorithm called Variable Step-Size Generalized Simulated Annealing(VSGSA) was applied to treating the data obtained by using an array of ion-electrodes in solutions containing mixtures of Na...A global optimum location algorithm called Variable Step-Size Generalized Simulated Annealing(VSGSA) was applied to treating the data obtained by using an array of ion-electrodes in solutions containing mixtures of Na+, K+, Ca2+. Unlike traditional optimization algorithms such as simplex procedure, VSGSA can be used to determine the model parameters without any priori information about the analytical system under investigation and overcome the disadvantage of simplex method which might converge to local extrema depending on the starting positions. The algorithm was applied to po-tentiometric determination of ions in mixture solutions.展开更多
Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible s...Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible substrate should be optimized for high-performance LIBs.Herein,cotton cloth(CC)is employed as a flexible substrate,and electroless plating is utilized to deposit a layer of Cu nanoparticles,which enhances the conductivity of CC and acts as a precursor for the active material,i.e.,CuO.The results reveal that the in situ etching and subsequent heat treatment converted Cu film into CuO nanowires on CC substrate.Moreover,carbon nano tubes(CNTs)are introduced to enhance the connectivity of CuO nano wires.Consequently,the CuO/CNT/CC electrode rendered a high areal capacity of>700μAh-cm^(-2)after100 charge/discharge cycles as well as excellent rate capability.The current work presents a novel route to develop desirable substrates for next-generation flexible Li-ion batteries.展开更多
Bimetal catalysts are good alternatives for nonenzymatic glucose sensors owing to their low cost, high activity, good conductivity, and ease of fabrication. In the present study, a self-supported CuNi/C electrode prep...Bimetal catalysts are good alternatives for nonenzymatic glucose sensors owing to their low cost, high activity, good conductivity, and ease of fabrication. In the present study, a self-supported CuNi/C electrode prepared by electrodepositing Cu nanoparticles on a Ni-based metal–organic framework(MOF) derivate was used as a non-enzymatic glucose sensor. The porous construction and carbon scaffold inherited from the Ni-MOF guarantee good kinetics of the electrode process in electrochemical glucose detection. Furthermore, Cu nanoparticles disturb the array structure of MOF derived films and evidently enhance their electrochemical performances in glucose detection. Electrochemical measurements indicate that the CuNi/C electrode possesses a high sensitivity of17.12 mA mM^(-1) cm^(-2), a low detection limit of 66.67 nM,and a wider linearity range from 0.20 to 2.72 mM. Additionally, the electrode exhibits good reusability, reproducibility, and stability, thereby catering to the practical use of glucose sensors. Similar values of glucose concentrations in human blood serum samples are detected with our electrode and with the method involving glucose-6-phosphate dehydrogenase; the results further demonstrate the practical feasibility of our electrode.展开更多
The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to s...The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice sig- nals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequen- cy analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to dis- tinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes＇ hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized.展开更多
Numerous scientists are in the pursuit of energy storage materials with high energy and high power density by assembly of electrochemically active materials into conductive scaffolds,owing to the emerging need for nex...Numerous scientists are in the pursuit of energy storage materials with high energy and high power density by assembly of electrochemically active materials into conductive scaffolds,owing to the emerging need for next-generation energy storage devices.In this architectures,the active materials bonded to the conductive scaffold can provide a robust and free-standing structure,which is crucial to the fabrication of materials with high gravimetric capacity.Thus,hierarchical copper-cobalt-nickel ternary oxide(CuCoNi-oxide) nanowire arrays grown from copper foam were successfully fabricated as freestanding anode materials for lithium ion batteries(LIBs).CuCoNi-oxide nanowire arrays could provide more active sites owing to the hyperbranched structure,leading to a better specific capacity of 1191 mAh/g,cycle performance of 73% retention in comparison to CuO nanowire structure,which exhibited a specific capacity of 1029 mAh/g and capacity retention of 43%,respectively.展开更多
Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays...Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays an important role during anesthesia.Currently,a high spatiotemporal resolution microdevice technology for the accurate detection of deep brain nuclei is lacking.In this research,four-shank 32-channel implantable microelectrode arrays(MEAs)were developed for the real-time recording of single-cell level neural information in rat hippocampal CA1.Platinum nanoparticles were modified onto the microelectrodes to substantially enhance the electrical properties of the microelectrode arrays.The modified MEAs exhibited low impedance(11.5±1 kΩ)and small phase delay(-18.5°±2.54°),which enabled the MEAs to record single-cell level neural information with a high signal-to-noise ratio.The MEAs were implanted into the CA1 nuclei of the anesthetized rats,and the electrophysiological signals were recorded under different degrees of anesthesia mediated by low-dose concentrations of isoflurane.The recorded signals were analyzed in depth.Isoflurane caused an inhibition of spike firing rate in hippocampal CA1 neurons,while inducing low-frequency oscillations in CA1,thus enhancing the low-frequency power of local field potentials.In this manner,the spike firing rate and the power of local field potentials in CA1 could characterize the degree of isoflurane anesthesia.The present study provides a technical tool to study the neural mechanisms of isoflurane anesthesia and a research method for monitoring the depth of isoflurane anesthesia in clinical practice.展开更多
Monitoring multiplexed biochemical markers is beneficial for the comprehensive evaluation of diabetes-associated complications.Techniques for multiplexed analyses in interstitial fluids have often been restricted by t...Monitoring multiplexed biochemical markers is beneficial for the comprehensive evaluation of diabetes-associated complications.Techniques for multiplexed analyses in interstitial fluids have often been restricted by the difficulties of electrode materials in accurately detecting chemicals in complex subcutaneous spaces.In particular,the signal stability of enzyme-based sensing electrodes often inevitably decreases due to enzyme degradation or interference in vivo.In this study,we developed a self-calibrating multiplexed microneedle(MN)electrode array(SC-MMNEA)capable of continuous,real-time monitoring of multiple types of bioanalytes(glucose,cholesterol,uric acid,lactate,reactive oxygen species[ROSs],Na+,K+,Ca2+,and pH)in the subcutaneous space.Each type of analyte was detected by a discrete MN electrode assembled in an integrated array with single-MN resolution.Moreover,this device utilized an MN-delivery-mediated self-calibration technique to address the inherent problem of decreased accuracy of implantable electrodes caused by long-term tissue variation and enzyme degradation,and this technique might increase the reliability of the MN sensors.Our results indicated that SC-MMNEA could provide real-time monitoring of multiplexed analyte concentrations in a rat model with good accuracy,especially after self-calibration.SC-MMNEA has the advantages of in situ and minimally invasive monitoring of physiological states and the potential to promote wearable devices for long-term monitoring of chemical species in vivo.展开更多
Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,...Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,and easy-to-perform solution for muscle health monitoring.However,current EIM platforms face a number of limitations,including large device size,wired connections,and instability of the electrode-skin interface,which limit their applicability for monitoring mus-cle movement.In this study,a miniature wireless EIM platform with a user-friendly smartphone app is proposed and devel-oped.The miniature,wireless,multi-frequency(20 kHz-1 MHz)EIM platform is equipped with flexible microneedle array elec-trodes(MAE).The advantages of MAEs over conventional electrodes were demonstrated by physical field modeling simula-tions and skin-electrode contact impedance comparison tests.The smartphone APP was developed to wirelessly operate the EIM platform,and to transmit and process real-time muscle impedance data.To validate its effectiveness,a seven-day adaptive fatigue training study was conducted,which demonstrated that the EIM platform was able to detect muscle adaptations and serve as a reliable indicator of fatigue.This study presents an innovative approach to applying EIM technology to muscle health monitoring and exercise testing,thereby advancing the development of personalized health management and athletic performance assessment.展开更多
The need for spatially-confined electrical stimulation is growing in biomedical applications,for example intracorticalstimulation and retinal implant,for enhancement of stimulating resolution.Local grounding technique...The need for spatially-confined electrical stimulation is growing in biomedical applications,for example intracorticalstimulation and retinal implant,for enhancement of stimulating resolution.Local grounding techniques have beenwidely explored to suppress undesired current spread.However,in conventional microneedle arrays like the Utaharray,grounding is typically achieved by assigning neighboring electrodes as ground or employing grounding wallaround stimulating electrode,which compromises spatial efficiency.In this work,we introduce,for the first time,abipolar microneedle electrode array(BMEA)that integrates two electrically-independent electrodes within each threedimensionalmicroneedle structure.The microtip electrode,located at the apex of the microneedle,delivers electricalstimulation,while the local ground electrode,embedded on the sidewall below the microtip,serves to locally confinethe spread of current.COMSOL Multiphysics simulations and ex vivo experiments using isolated mouse retinademonstrated that activating the local ground electrode effectively restricts current diffusion,enabling more focusedand localized stimulation.This approach offers a compact and efficient solution for focal electrical stimulation withenhanced spatial resolution,providing a promising platform for advanced neural interfacing systems in variousbiomedical fields.展开更多
Electrochemical water splitting,allowing energy conversion from renewable resources into non-polluting chemical fuels,is vital for future sustainable energy systems,and great efforts have been made for developing effi...Electrochemical water splitting,allowing energy conversion from renewable resources into non-polluting chemical fuels,is vital for future sustainable energy systems,and great efforts have been made for developing efficient and cheap bifunctional electrocatalysts.Herein we report a bifunctional vanadium-doped Ni_(3)S_(2) nanorod array electrode for overall water splitting in alkaline media.To afford a catalytic current of 10 mA cm^(-2),the designed V-Ni_(3)S_(2) electrode only requires overpotentials of 133 mV for hydrogen evolution and 148 mV for oxygen generation,meanwhile showing high long-term stability.The excellent catalytic properties are attributed to the V dopant and geometric advantages of the nanorod array.The V-Ni_(3)S_(2) electrodes are simultaneously utilized as cathode and anode in one two-electrode cell for overall water splitting,exhibiting a cell voltage of 1.421 V at 10 mA cm^(-2).The water splitting in this cell can also be feasibly driven by a single-cell AA battery(1.5 V).Our report shows substantial advancement in the exploration of efficient bifunctional electrocatalysts for water splitting.展开更多
Developing highly efficient and non-noble-metal catalysts is of great importance for electrochemical energy storage and conversion.In this communication,we report the development of a porous Ni_(3)N nanosheet array on...Developing highly efficient and non-noble-metal catalysts is of great importance for electrochemical energy storage and conversion.In this communication,we report the development of a porous Ni_(3)N nanosheet array on carbon cloth(Ni_(3)N NA/CC)as a high-performance and durable electrocatalyst for urea oxidation.To drive 10 mA cm^(-2),this Ni_(3)N NA/CC only demands a potential of 1.35 V in 1.0 M KOH with 0.33 M urea.The high catalytic activity of the hydrogen evolution reaction enables Ni_(3)N NA/CC as a bifunctional catalyst electrode for electrochemical hydrogen production and the two-electrode electrolyzer is capable of offering 10 mA cm^(-2) at a cell voltage of only 1.44 V,120 mV less than that for the ureafree counterpart.展开更多
It is crucial to develop non-noble metal bifunctional electrocatalysts with high activity and favorable stability for overall water splitting under basic conditions for renewable-energy conversion techniques.Direct as...It is crucial to develop non-noble metal bifunctional electrocatalysts with high activity and favorable stability for overall water splitting under basic conditions for renewable-energy conversion techniques.Direct assembly of active materials on carbon cloth is a promising approach to realize flexible electrodes for electrocatalysis.展开更多
Hierarchical copper cobalt sulfide nanobelt array structures with well-defined morphology control are first reported as high energy density electrode materials for asymmetric supercapacitors using a simple two-step so...Hierarchical copper cobalt sulfide nanobelt array structures with well-defined morphology control are first reported as high energy density electrode materials for asymmetric supercapacitors using a simple two-step solvothermal method.Through appropriate control of the reaction time and sulfide ion concentration during the sulfidation reactions,saturated sulfidation was achieved while ensuring the morphology,structural integrity,and stability of the precursor.Subsequently,the unique morphological structure of the CuCo2S4 nanobelt arrays resulted in high availability and excellent conductivity of the electrochemically active sites.The CuCo2S4 electrode achieved a high specific capacity reaching 1014 C g^(−1) at 1 A g^(−1),and 1.95 C cm^(−2) at 1 mA cm^(−2) as well as excellent cycling stability of 93.82% after 5000 cycles at 20 mA cm^(−2),superior to previous values for ternary transition metal sulfides.In addition,a stable output voltage with a 1.6 V aqueous asymmetric device was assembled using prepared mesoporous nitrogen-doped double-layer hollow carbon microspheres as the negative electrode and CuCo2S4 as the positive electrode.The assembled device exhibited a high energy density of 40.2 W h kg^(−1) at a power density of 799.1 W kg^(−1) with a high capacity retention (90.89% after 5000 cycles at 20 mA cm^(−2)).More importantly,two devices in series could light up three red LEDs for more than 20 min and rotate a small motor for 15 s.Thus,the results of this study provide a strategy for the design and manufacture of other ternary metal sulfides for high-performance energy storage devices.展开更多
基金supported in part by the National Natural Science Foundation of China(Grant No.62104056)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LQ21F010010)+4 种基金the National Natural Science Foundation of China(Grant Nos.62141409 and 62204204)the National Key R&D Program of China(Grant No.2022ZD0208602)the Zhejiang Provincial Key Research&Development Fund(Grant Nos.2019C04003 and 2021C01041)the Shanghai Sailing Program(Grant No.21YF1451000)the Key Research and Development Program of Shaanxi(Grant No.2022GY-001).
文摘Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stability have hindered their large-scale commercial application.Herein,aflexible capacitive pressure sensor based on an interdigital electrode structure with two porous microneedle arrays(MNAs)is pro-posed.The porous substrate that constitutes the MNA is a mixed product of polydimethylsiloxane and NaHCO3.Due to its porous and interdigital structure,the maximum sensitivity(0.07 kPa-1)of a porous MNA-based pressure sensor was found to be seven times higher than that of an imporous MNA pressure sensor,and it was much greater than that of aflat pressure sensor without a porous MNA structure.Finite-element analysis showed that the interdigital MNA structure can greatly increase the strain and improve the sensitivity of the sen-sor.In addition,the porous MNA-based pressure sensor was found to have good stability over 1500 loading cycles as a result of its bilayer parylene-enhanced conductive electrode structure.Most importantly,it was found that the sensor could accurately monitor the motion of afinger,wrist joint,arm,face,abdomen,eye,and Adam’s apple.Furthermore,preliminary semantic recognition was achieved by monitoring the movement of the Adam’s apple.Finally,multiple pressure sensors were integrated into a 33 array to detect a spatial pressure distribu-×tion.Compared to the sensors reported in previous works,the interdigital electrode structure presented in this work improves sensitivity and stability by modifying the electrode layer rather than the dielectric layer.
文摘Objective:To investigate the spatial gradient of intraoperative impedance across the cochlear electrode array in pediatric cochlear implant recipients and assess its potential as a physiological indicator for the electrode-neural interface.Methods:A prospective observational study involving 56 pediatric patients underwent cochlear implantation with Cochlear Nucleus devices.Intraoperative polarized impedance and electrically evoked compound action potential(ECAP)threshold were recorded across all 1232 electrodes using AutoNRT software.Eight electrodes with open-or short-circuit were excluded,leaving 1,224 for analysis.Impedance values were categorized by cochlear region(basal,middle,apical),and electrodes with elevated impedance(10-20 kΩ)were analyzed for regional distribution and clinical relevance.Data were analyzed for spatial patterns and correlation with the ECAP threshold profiles.Results:A consistent basal-to-apical increase in impedance was observed(7.7±1.9,9.2±1.4,10.8±1.5 kΩ;p<0.001).Impedance and ECAP threshold were weakly correlated(ρ=-0.20,p<0.001;β=-1.26,p<0.001),with a positive association in the apical region(ρ=0.12,p=0.048).Electrodes with higher impedance(1020 kΩ)were less likely to show elevated or absent TNRT(OR=0.175,p=0.02).The impedance gradient persisted across age groups and was significantly correlated with ECAP threshold patterns.Conclusion:Intraoperative impedance monitoring reveals a strong and physiologically consistent gradient,with higher values in apical electrodes.This gradient reflects anatomical and tissue interface variations,which may offer a valuable physiological indicator for intraoperative electrode positioning and neural interface integrity.
基金supported by the China Capital Health Research and Development of Special (No. 2018-14111)the National Natural Science Foundation of China (grant No. 62004007 and No. 82027805)the China Postdoctoral Science Foundation Grant (No. 2021M700258)
文摘Microneedle array(MNA)electrodes are an effective solution to achieve high-quality surface biopotential recording without the coordination of conductive gel and are thus very suitable for long-term wearable applications.Existing schemes are limited by flexibility,biosafety,and manufacturing costs,which create large barriers for wider applications.Here,we present a novel flexible MNA electrode that can simultaneously achieve flexibility of the substrate to fit a curved body surface,robustness of microneedles to penetrate the skin without fracture,and a simplified process to allow mass production.The compatibility with wearable wireless systems and the short preparation time of the electrodes significantly improves the comfort and convenience of electrophysiological recording.The normalized electrode–skin contact impedance reaches 0.98 kΩcm^(2)at 1 kHz and 1.50 kΩcm^(2)at 10 Hz,a record low value compared to previous reports and approximately 1/250 of the standard electrodes.The morphology,biosafety,and electrical/mechanical properties are fully characterized,and wearable recordings with a high signal-to-noise ratio and low motion artifacts are realized.The first reported clinical study of microneedle electrodes for surface electrophysiological monitoring was conducted in tens of healthy and sleep-disordered subjects with 44 nights of recording(over 8 h per night),providing substantial evidence that the electrodes can be leveraged to substitute for clinical standard electrodes.
基金Supported by the National Natural Science Foundation of China
文摘Conducting polymers have been studied extensively. An interesting property of the conducting polymer is that the conductivity of some polymers, such as polypyrrolc, polyaniline, poly(3-methylthiophene) etc. , is affected by the voltage applied to them. For polypyrrole, the oxidized state is an electronic conductor and the reduced state is essentially insulating. Using this property, one can fabricate the polymer-based electronic devices. Experimental results of Pickun
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LQ23E010004)the National Key Research and Development Program of China(No.2021YFB3200801)。
文摘Intracellular electrophysiological research is vital for biological and medical research.Traditional planar microelectrode arrays(MEAs)have disadvantages in recording intracellular action potentials due to the loose cell-electrode interface.To investigate intracellular electrophysiological signals with high sensitivity,electroporation was used to obtain intracellular recordings.In this study,a biosensing system based on a nanoporous electrode array(NPEA)integrating electrical perforation and signal acquisition was established to dynamically and sensitively record the intracellular potential of cardiomyocytes over a long period of time.Moreover,nanoporous electrodes can induce the protrusion of cell membranes and enhance cell-electrode interfacial coupling,thereby facilitating effective electroporation.Electrophysiological signals over the entire recording process can be quantitatively and segmentally analyzed according to the signal changes,which can equivalently reflect the dynamic evolution of the electroporated cardiomyocyte membrane.We believe that the low-cost and high-performance nanoporous biosensing platform suggested in this study can dynamically record intracellular action potential,evaluate cardiomyocyte electroporation,and provide a new strategy for investigating cardiology pharmacological science.
基金supported by the National Natural Science Foundation of China,Nos.61534003 (to ZGW) and 61874024 (to ZGW)。
文摘Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.
基金the financial support from China Aviation Science Foundation (04H52055).
文摘Process technology of multiple cylindrical micro-pins by wire-electrical discharge machining （wire-EDM） and electrochemical etching was presented. A row of rectangular micro-columns were machined by wire-EDM and then machined into cylindrical shape by electrochemical etching. However, the shape of the multiple electrodes and the consistent sizes of the electrodes row are not easy to be controlled. In the electrochemical process, the shape of the cathode electrode determines the current density distribution on the anode and so the forming of multiple electrodes. This paper proposes a finite element method （FEM） to accurately optimize the electrode profile. The microelectrodes row with uniformity diameters with size from hundreds micrometers to several decades could be fabricated, and mathematical model controlling the shape and diameter of multiple microelectrodes was provided. Furthermore, a good agreement between experimental and theoretical results was confirmed.
基金Supported by the National Natural Science Foundation of China Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Academia Sinica
文摘A global optimum location algorithm called Variable Step-Size Generalized Simulated Annealing(VSGSA) was applied to treating the data obtained by using an array of ion-electrodes in solutions containing mixtures of Na+, K+, Ca2+. Unlike traditional optimization algorithms such as simplex procedure, VSGSA can be used to determine the model parameters without any priori information about the analytical system under investigation and overcome the disadvantage of simplex method which might converge to local extrema depending on the starting positions. The algorithm was applied to po-tentiometric determination of ions in mixture solutions.
基金the National Natural Science Foundation of China(Nos.21701022 and51690161)the Fundamental Research Funds for the Central Universities(Nos.N182505037 and N182410001)+2 种基金the Young Elite Scientists Sponsorship Program by CAST(No.2018QNRC001)the Liao Ning Revitalization Talents Program(No.XLYC1807214)the National Training Program of Innovation and Entrepreneurship for Undergraduates(No.201910145260)。
文摘Flexible,lightweight and high conductivity substrates are required for the development of next-generation flexible Li-ion batteries(LIBs).In addition,the interfacial strength between the active material and flexible substrate should be optimized for high-performance LIBs.Herein,cotton cloth(CC)is employed as a flexible substrate,and electroless plating is utilized to deposit a layer of Cu nanoparticles,which enhances the conductivity of CC and acts as a precursor for the active material,i.e.,CuO.The results reveal that the in situ etching and subsequent heat treatment converted Cu film into CuO nanowires on CC substrate.Moreover,carbon nano tubes(CNTs)are introduced to enhance the connectivity of CuO nano wires.Consequently,the CuO/CNT/CC electrode rendered a high areal capacity of>700μAh-cm^(-2)after100 charge/discharge cycles as well as excellent rate capability.The current work presents a novel route to develop desirable substrates for next-generation flexible Li-ion batteries.
基金supported by the National Natural Science Foundation of China (No. 21776052)the Natural Science Foundation of Heilongjiang Province (No. QC2016010)the Fundamental Research Funds for the Central Universities (No. HIT. IBRSEM. A. 201407)
文摘Bimetal catalysts are good alternatives for nonenzymatic glucose sensors owing to their low cost, high activity, good conductivity, and ease of fabrication. In the present study, a self-supported CuNi/C electrode prepared by electrodepositing Cu nanoparticles on a Ni-based metal–organic framework(MOF) derivate was used as a non-enzymatic glucose sensor. The porous construction and carbon scaffold inherited from the Ni-MOF guarantee good kinetics of the electrode process in electrochemical glucose detection. Furthermore, Cu nanoparticles disturb the array structure of MOF derived films and evidently enhance their electrochemical performances in glucose detection. Electrochemical measurements indicate that the CuNi/C electrode possesses a high sensitivity of17.12 mA mM^(-1) cm^(-2), a low detection limit of 66.67 nM,and a wider linearity range from 0.20 to 2.72 mM. Additionally, the electrode exhibits good reusability, reproducibility, and stability, thereby catering to the practical use of glucose sensors. Similar values of glucose concentrations in human blood serum samples are detected with our electrode and with the method involving glucose-6-phosphate dehydrogenase; the results further demonstrate the practical feasibility of our electrode.
基金supported by the National Natural Science Foundation of China,No.60672001Special Fund of Education Department of Shaanxi Province,China,No.05JC03
文摘The current use of hearing aids and artificial cochleas for deaf-mute individuals depends on their auditory nerve. Skin-hearing technology, a patented system developed by our group, uses a cutaneous sensory nerve to substitute for the auditory nerve to help deaf-mutes to hear sound. This paper introduces a new solution, multi-channel-array skin-hearing technology, to solve the problem of speech discrimination. Based on the filtering principle of hair cells, external voice sig- nals at different frequencies are converted to current signals at corresponding frequencies using electronic multi-channel bandpass filtering technology. Different positions on the skin can be stimulated by the electrode array, allowing the perception and discrimination of external speech signals to be determined by the skin response to the current signals. Through voice frequen- cy analysis, the frequency range of the band-pass filter can also be determined. These findings demonstrate that the sensory nerves in the skin can help to transfer the voice signal and to dis- tinguish the speech signal, suggesting that the skin sensory nerves are good candidates for the replacement of the auditory nerve in addressing deaf-mutes＇ hearing problems. Scientific hearing experiments can be more safely performed on the skin. Compared with the artificial cochlea, multi-channel-array skin-hearing aids have lower operation risk in use, are cheaper and are more easily popularized.
基金financially supported by the National Natural Science Foundation of China (No.21975163)China Postdoctoral Science Foundation (No.2018M633125)。
文摘Numerous scientists are in the pursuit of energy storage materials with high energy and high power density by assembly of electrochemically active materials into conductive scaffolds,owing to the emerging need for next-generation energy storage devices.In this architectures,the active materials bonded to the conductive scaffold can provide a robust and free-standing structure,which is crucial to the fabrication of materials with high gravimetric capacity.Thus,hierarchical copper-cobalt-nickel ternary oxide(CuCoNi-oxide) nanowire arrays grown from copper foam were successfully fabricated as freestanding anode materials for lithium ion batteries(LIBs).CuCoNi-oxide nanowire arrays could provide more active sites owing to the hyperbranched structure,leading to a better specific capacity of 1191 mAh/g,cycle performance of 73% retention in comparison to CuO nanowire structure,which exhibited a specific capacity of 1029 mAh/g and capacity retention of 43%,respectively.
基金sponsored by the National Natural Science Foundation of China(T2293731,61960206012,62121003,62171434,61971400,61975206,and 61973292)the Scientific Instrument Developing Project of the Chinese Academy of Sciences(GJJSTD20210004)+1 种基金the National Key Research and Development Program(2022YFC2402501,2022YFB3205602)Major Program of Scientific and Technical Innovation 2030(2021ZD0201603).
文摘Timely monitoring of anesthesia status during surgery is important to prevent an overdose of isoflurane anesthesia.Therefore,in-depth studies of the neural mechanisms of anesthetics are warranted.Hippocampal CA1 plays an important role during anesthesia.Currently,a high spatiotemporal resolution microdevice technology for the accurate detection of deep brain nuclei is lacking.In this research,four-shank 32-channel implantable microelectrode arrays(MEAs)were developed for the real-time recording of single-cell level neural information in rat hippocampal CA1.Platinum nanoparticles were modified onto the microelectrodes to substantially enhance the electrical properties of the microelectrode arrays.The modified MEAs exhibited low impedance(11.5±1 kΩ)and small phase delay(-18.5°±2.54°),which enabled the MEAs to record single-cell level neural information with a high signal-to-noise ratio.The MEAs were implanted into the CA1 nuclei of the anesthetized rats,and the electrophysiological signals were recorded under different degrees of anesthesia mediated by low-dose concentrations of isoflurane.The recorded signals were analyzed in depth.Isoflurane caused an inhibition of spike firing rate in hippocampal CA1 neurons,while inducing low-frequency oscillations in CA1,thus enhancing the low-frequency power of local field potentials.In this manner,the spike firing rate and the power of local field potentials in CA1 could characterize the degree of isoflurane anesthesia.The present study provides a technical tool to study the neural mechanisms of isoflurane anesthesia and a research method for monitoring the depth of isoflurane anesthesia in clinical practice.
基金support from the National Natural Sci-ence Foundation of China(grant nos.T2225010,32171399,and 32171456)Guangdong Basic and Applied Basic Research Foundation(grant no.2023A1515011267)+1 种基金Science and Technalogy Program of Guangzhou,China(grant nos.2024B03J0121 and 2024B03J1284)the Independent Fund of the State Key Laboratory of Optoelectronic Ma-terials and Technologies(Sun YatSen University)under grant no.
文摘Monitoring multiplexed biochemical markers is beneficial for the comprehensive evaluation of diabetes-associated complications.Techniques for multiplexed analyses in interstitial fluids have often been restricted by the difficulties of electrode materials in accurately detecting chemicals in complex subcutaneous spaces.In particular,the signal stability of enzyme-based sensing electrodes often inevitably decreases due to enzyme degradation or interference in vivo.In this study,we developed a self-calibrating multiplexed microneedle(MN)electrode array(SC-MMNEA)capable of continuous,real-time monitoring of multiple types of bioanalytes(glucose,cholesterol,uric acid,lactate,reactive oxygen species[ROSs],Na+,K+,Ca2+,and pH)in the subcutaneous space.Each type of analyte was detected by a discrete MN electrode assembled in an integrated array with single-MN resolution.Moreover,this device utilized an MN-delivery-mediated self-calibration technique to address the inherent problem of decreased accuracy of implantable electrodes caused by long-term tissue variation and enzyme degradation,and this technique might increase the reliability of the MN sensors.Our results indicated that SC-MMNEA could provide real-time monitoring of multiplexed analyte concentrations in a rat model with good accuracy,especially after self-calibration.SC-MMNEA has the advantages of in situ and minimally invasive monitoring of physiological states and the potential to promote wearable devices for long-term monitoring of chemical species in vivo.
文摘Accurate quantification of exercise interventions and changes in muscle function is essential for personalized health management.Electrical impedance myography(EIM)technology offers an innovative,noninvasive,painless,and easy-to-perform solution for muscle health monitoring.However,current EIM platforms face a number of limitations,including large device size,wired connections,and instability of the electrode-skin interface,which limit their applicability for monitoring mus-cle movement.In this study,a miniature wireless EIM platform with a user-friendly smartphone app is proposed and devel-oped.The miniature,wireless,multi-frequency(20 kHz-1 MHz)EIM platform is equipped with flexible microneedle array elec-trodes(MAE).The advantages of MAEs over conventional electrodes were demonstrated by physical field modeling simula-tions and skin-electrode contact impedance comparison tests.The smartphone APP was developed to wirelessly operate the EIM platform,and to transmit and process real-time muscle impedance data.To validate its effectiveness,a seven-day adaptive fatigue training study was conducted,which demonstrated that the EIM platform was able to detect muscle adaptations and serve as a reliable indicator of fatigue.This study presents an innovative approach to applying EIM technology to muscle health monitoring and exercise testing,thereby advancing the development of personalized health management and athletic performance assessment.
基金supported in part by KIST(Korea Institute of Science and Technology)institutional grants(Nos.2E33881 and 2E33682)in part by the National R&D Program through the National Research Foundation(NRF)of Korea,funded by the Ministry of Science and ICT(Nos.2023R1A2C2003786,RS-2023-00302397,RS-2025-25465381,and RS-2025-00514523).
文摘The need for spatially-confined electrical stimulation is growing in biomedical applications,for example intracorticalstimulation and retinal implant,for enhancement of stimulating resolution.Local grounding techniques have beenwidely explored to suppress undesired current spread.However,in conventional microneedle arrays like the Utaharray,grounding is typically achieved by assigning neighboring electrodes as ground or employing grounding wallaround stimulating electrode,which compromises spatial efficiency.In this work,we introduce,for the first time,abipolar microneedle electrode array(BMEA)that integrates two electrically-independent electrodes within each threedimensionalmicroneedle structure.The microtip electrode,located at the apex of the microneedle,delivers electricalstimulation,while the local ground electrode,embedded on the sidewall below the microtip,serves to locally confinethe spread of current.COMSOL Multiphysics simulations and ex vivo experiments using isolated mouse retinademonstrated that activating the local ground electrode effectively restricts current diffusion,enabling more focusedand localized stimulation.This approach offers a compact and efficient solution for focal electrical stimulation withenhanced spatial resolution,providing a promising platform for advanced neural interfacing systems in variousbiomedical fields.
基金support from the Natural Science Foundation(2016GGX104019)of Shandong Province.
文摘Electrochemical water splitting,allowing energy conversion from renewable resources into non-polluting chemical fuels,is vital for future sustainable energy systems,and great efforts have been made for developing efficient and cheap bifunctional electrocatalysts.Herein we report a bifunctional vanadium-doped Ni_(3)S_(2) nanorod array electrode for overall water splitting in alkaline media.To afford a catalytic current of 10 mA cm^(-2),the designed V-Ni_(3)S_(2) electrode only requires overpotentials of 133 mV for hydrogen evolution and 148 mV for oxygen generation,meanwhile showing high long-term stability.The excellent catalytic properties are attributed to the V dopant and geometric advantages of the nanorod array.The V-Ni_(3)S_(2) electrodes are simultaneously utilized as cathode and anode in one two-electrode cell for overall water splitting,exhibiting a cell voltage of 1.421 V at 10 mA cm^(-2).The water splitting in this cell can also be feasibly driven by a single-cell AA battery(1.5 V).Our report shows substantial advancement in the exploration of efficient bifunctional electrocatalysts for water splitting.
文摘Developing highly efficient and non-noble-metal catalysts is of great importance for electrochemical energy storage and conversion.In this communication,we report the development of a porous Ni_(3)N nanosheet array on carbon cloth(Ni_(3)N NA/CC)as a high-performance and durable electrocatalyst for urea oxidation.To drive 10 mA cm^(-2),this Ni_(3)N NA/CC only demands a potential of 1.35 V in 1.0 M KOH with 0.33 M urea.The high catalytic activity of the hydrogen evolution reaction enables Ni_(3)N NA/CC as a bifunctional catalyst electrode for electrochemical hydrogen production and the two-electrode electrolyzer is capable of offering 10 mA cm^(-2) at a cell voltage of only 1.44 V,120 mV less than that for the ureafree counterpart.
基金the National Natural Science Foundation of China(21675127)the Shaanxi Provincial Science Fund for Distinguished Young Scholars(2018JC-011)+1 种基金the Development Project of Qinghai Provincial Key Laboratory(2017-ZJ-Y10)the Capacity Building Project of Engineering Research Center of Qinghai Province(2017-GX-G03).
文摘It is crucial to develop non-noble metal bifunctional electrocatalysts with high activity and favorable stability for overall water splitting under basic conditions for renewable-energy conversion techniques.Direct assembly of active materials on carbon cloth is a promising approach to realize flexible electrodes for electrocatalysis.
基金supported by the National Natural Science Foundation of China(No.21271082 and 21371068)Open Fund Project of Key Laboratory of Electrochemical Energy Storage and Energy Conversion in Hainan Province(KFKT2019001).
文摘Hierarchical copper cobalt sulfide nanobelt array structures with well-defined morphology control are first reported as high energy density electrode materials for asymmetric supercapacitors using a simple two-step solvothermal method.Through appropriate control of the reaction time and sulfide ion concentration during the sulfidation reactions,saturated sulfidation was achieved while ensuring the morphology,structural integrity,and stability of the precursor.Subsequently,the unique morphological structure of the CuCo2S4 nanobelt arrays resulted in high availability and excellent conductivity of the electrochemically active sites.The CuCo2S4 electrode achieved a high specific capacity reaching 1014 C g^(−1) at 1 A g^(−1),and 1.95 C cm^(−2) at 1 mA cm^(−2) as well as excellent cycling stability of 93.82% after 5000 cycles at 20 mA cm^(−2),superior to previous values for ternary transition metal sulfides.In addition,a stable output voltage with a 1.6 V aqueous asymmetric device was assembled using prepared mesoporous nitrogen-doped double-layer hollow carbon microspheres as the negative electrode and CuCo2S4 as the positive electrode.The assembled device exhibited a high energy density of 40.2 W h kg^(−1) at a power density of 799.1 W kg^(−1) with a high capacity retention (90.89% after 5000 cycles at 20 mA cm^(−2)).More importantly,two devices in series could light up three red LEDs for more than 20 min and rotate a small motor for 15 s.Thus,the results of this study provide a strategy for the design and manufacture of other ternary metal sulfides for high-performance energy storage devices.
