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
Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative dist...Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative distribution of the in-plane and out-of-plane displacement of the mode across the thickness of the plate will determine the sensitivity of the mode to a particular loading condition. By considering the dispersion and multi-mode characteristics of guided waves, an interdigital polyvi- nylidene fluoride （PVDF） transducer is designed to realize the mode selection of gnided waves, and a single a0 mode is used for guided wave detection. Fouling detection experiments are conducted in the laboratory using epoxy adhesive on a thin plate. Using the interdigital PVDF transducer, three fouled areas are detected. Using one of the time-frequency analysis methods, the waveforms are further processed. This also demonstrates the validity of this method of fouling detection.展开更多
The electro-mechanical coupling behaviors of ferroelectric devices with interdigital electrodes may become complicated due to the material inhomogeneity and local field concentration under the complex working conditio...The electro-mechanical coupling behaviors of ferroelectric devices with interdigital electrodes may become complicated due to the material inhomogeneity and local field concentration under the complex working conditions.In this paper,a ferroelectric model,drawn from the typical interdigital electrode structure of a ferroelectric sensor,is established based on phase field theory,to study the polarization evolution and explore the evolution laws in ferroelectrics.Numerical results show that there appears ferroelectric creep even under an applied electric field below the coercive field value.Also,the configurational force theory is introduced to investigate the mechanical behaviors related to polarization switching in the ferroelectric samples with interdigital electrodes.It is found that configurational force and polarization have similar evolution laws in both time evolving and space distribution.And considering the configurational force as the driving force,it is possible to predict the potential direction of polarization evolution and explore its evolution mechanism in ferroelectrics,demonstrating the configurational force as a useful parameter for describing mechanical behavior during the polarization evolution and a powerful tool for investigating the evolution mechanism of microstructure with coupling effects in ferroelectric materials.展开更多
Currently,the increasing demands for portable,implantable,and wearable electronics have triggered the interest in miniaturized energy storage devices.Different from conventional energy storage devices,interdigital mic...Currently,the increasing demands for portable,implantable,and wearable electronics have triggered the interest in miniaturized energy storage devices.Different from conventional energy storage devices,interdigital microbatteries(IMBs) are free of separators and prepared on a single substrate,potentially achieving a short ionic diffusion path and better performance.Meanwhile,they can be easily fabricated and integrated into on-chip miniaturized electronics,holding the promise to provide long-lasting power for advanced microelectronic devices.To date,while many seminal works have been reviewed the topic of microbatteries,there is no work that systematically summarizes the development of IMBs of high energy density and stable voltage platforms from fabrication,functionalization to integration.The current review focuses on the most recent progress in IMBs,discussing advanced micromachining techniques with compatible features to construct high-performance IMBs with smart functions and intelligent integrated systems.The future opportunities and challenges of IMBs are also highlighted,calling for more efforts in this dynamic and fast-growing research field.展开更多
Polymer-based materials with patterned functional particles have been used to develop smart devices with multiple functionalities.This paper presents a novel method to pattern microscale particles into biocompatible p...Polymer-based materials with patterned functional particles have been used to develop smart devices with multiple functionalities.This paper presents a novel method to pattern microscale particles into biocompatible polyethylene glycol diacrylate(PEGDA)fluid through a designed surface acoustic wave(SAW)device with slanted-finger interdigital transducers(SFITs).By applying signals of different frequencies,the SFITs can excite SAWs with various wavelengths to pattern the microscale particles.The structural design and working principle of the SAW device with SFITs are firstly presented.To investigate the generation of standing SAWs and pressure field distributions of the SAW device with SFITs,a numerical model was developed.Simulation results showed that different strip-shape patterned pressure fields can be generated,and the period and width of adjacent strips can be adjusted by changing the frequencies of the excitation signals.Experiments were performed to verify that the microscale particles in the PEGDA solution can be successfully patterned into strip-shape patterns with various positions,periods,and widths.The results obtained in this study demonstrate that the developed method of using an SAW device with SFITs can be used for tunable patterning of microscale particles in solutions,and shows great potential for biomedical and microfluidic applications.展开更多
Objective:Interdigital infection,as a neglected disease,is frequently misdiagnosed as simple tinea pedis which caused by purely dermatophyte induced.It remains intractable to treatments because of high recurrence rate...Objective:Interdigital infection,as a neglected disease,is frequently misdiagnosed as simple tinea pedis which caused by purely dermatophyte induced.It remains intractable to treatments because of high recurrence rates and potential complications.However,the optimal diagnosis and treatment regimens have not been firmly established.This study aimed to investigate the presentation,etiology,predisposing factors,occurrence regularity,and therapeutic approaches of interdigital infection in Shanghai,China.Methods:A cross-sectional study was conducted at Shanghai Dermatology Hospital in 2019,and data from 57 patients with acute interdigital inflammation were collected.Clinical features and medical histories including blood,bacterial,and mycological examination,culture test,drug susceptibility test results,and follow-up data were analyzed for pathogenic agents.Patients received etiological therapy and were followed up for 1 year.McNemar’s tests were used for comparison of positive rates of direct microscopy and cultures.Results:We found Pseudomonas aeruginosa(40.35%),Staphylococcus aureus(36.84%),and other bacteria(22.80%).The rate of positive fungus culture after bacterial infection recovery was significantly higher than that at the first visit(86.67%vs.36.00%,P=0.001).Compared to other bacteria,Pseudomonas aeruginosa interdigital infection was more inclined to co-infect with fungal agents and was frequently seen in spring and autumn and in patients aged 60-69 years.Interdigital infection caused by Staphylococcus aureus occurred more frequently in the summer and in patients aged 31-40 years.We found that levofloxacin had excellent therapeutic effects for interdigital infection.Conclusion:Our findings may provide important information for establishing diagnostic guidelines and effective treatment,and subsequently,help reduce the rate of recurrence and improve patient outcomes following interdigital infection.展开更多
This work proposes a fabrication technique that can achieve wafer-level preparation of flexible interdigital electrodes(IDEs)with high-density and large-thickness(HD<).Utilizing these HD< flexible IDEs,we ...This work proposes a fabrication technique that can achieve wafer-level preparation of flexible interdigital electrodes(IDEs)with high-density and large-thickness(HD<).Utilizing these HD< flexible IDEs,we developed a flexible humidity sensor that employs a composite material made of nanowire bundles with carbon quantum dots(CQDBs)for humidity sensitivity.In this device,the composite material facilitates high absorption and capillary condensation of water molecules across various relative humidity(RH)conditions,while the HD< IDEs enhance the effective sensing area.Consequently,we achieve a flexible humidity sensor with exceptional performance.This sensor not only boasts key attributes such as low cost,easy fabrication,and straightforward operation but also establishes a foundation for extensive humidity sensing applications.In comparison to other devices utilizing small-thickness and low-density IDEs,our sensor demonstrates remarkable 2.5-fold and 5.8-fold increase in sensitivity across humidity ranges of 7%-59%RH and 59%-97%RH,respectively.To explore the practical applications of the device,we demonstrate its functionality in diaper humidity detection.With characteristics of wearability and durability,the sensor shows significant potential for humidity monitoring in wearable electronics.展开更多
Alternating current(AC)driven quantum dots(QDs)light-emitting diodes have attracted widespread attention due to their unique optoelectronic performance.An ACdriven device with an interdigital electrode structure is pr...Alternating current(AC)driven quantum dots(QDs)light-emitting diodes have attracted widespread attention due to their unique optoelectronic performance.An ACdriven device with an interdigital electrode structure is proposed.The devices exhibit AC electroluminescence(EL)with driving frequency and different frequency responses due to the introduction of P(VDF-TrFE-CFE).The optical and electrical characteristics of the device under various applied voltages and driving frequencies are studied.Unlike the conventional driving mode where carriers are continuously injected into the device,the carriers undergo periodic motion under an AC field.Therefore,there exists an optimal driving frequency that maximizes the EL intensity of the device.Based on the experimental results,the operational mechanism of the device is analyzed,and a carrier transport model is proposed to elucidate the underlying factors contributing to the presence of an optimal driving frequency.Moreover,a model for the device is proposed and its accuracy is verified.From a circuit perspective,the EL behavior of devices at various driving frequencies is analyzed,thereby further confirming the accuracy of the proposed device working mechanism.We believe the work can provide guidance for obtaining advanced QD-based lightemitting technology.展开更多
The application of frequency selection surfaces(FSSs)is limited by large area,narrow bandwidth,low stopband inhibition and large ripple in the passband.A method for designing high-order wide band miniaturized-element ...The application of frequency selection surfaces(FSSs)is limited by large area,narrow bandwidth,low stopband inhibition and large ripple in the passband.A method for designing high-order wide band miniaturized-element frequency selective surface(MEFSS)with capacitance loading is introduced.The proposed structure is composed of multiply sub-wavelength interdigital capacitance layer,sub-wavelength inductive wire grids separated by dielectric substrates.A simple equivalent circuit model,composed of short transmission lines coupled together with shunt inductors and capacitors,is presented for this structure.Using the equivalent circuit model and electromagnetic(EM)model,an analytical synthesis procedure is developed that can be used to synthesize the MEFSS from its desired system-level performance indicators such as the center frequency of operation,bandwidth and stopband inhibition.Using this synthesis procedure,a prototype of the proposed MEFSS with a third-order bandpass response,center frequency of 2.75 GHz,fractional bandwidth of 8%is designed,fabricated,and measured.The measurement results confirm the theoretical predictions and the design procedure of the structure and demonstrate that the proposed MEFSS has a stable frequency response with respect to the angle of incidence of the EM wave in the±30°range incidence,and the in-band return loss is greater than 18 dB,and the rejection in the stopband is greater than 25 dB at the frequency of 3.2 GHz.展开更多
Metal-semiconductor-metal photodetectors on semi-insulating Ga As with interdigital electrodes showed significant enhancement in the spectral response in the near-infrared region as the electrode spacing is reduced. T...Metal-semiconductor-metal photodetectors on semi-insulating Ga As with interdigital electrodes showed significant enhancement in the spectral response in the near-infrared region as the electrode spacing is reduced. The photocurrent for the device with 5 μm interdigital spacing is five orders of magnitude higher than the dark current, and the room temperature detectivity is on the order of 2.4 × 1012cm Hz1∕2W-1at 5 V bias. Furthermore,the spectral response of this device possesses strong dependence on the polarization of incident light showing potential plasmonic effects with only microscale dimensions. These experimental data were analyzed using optical simulation to confirm the response of the devices.展开更多
In the rapidly evolving field of modern technology,near-infrared(NIR)photodetectors are extremely crucial for efficient and reliable optical communications.The graphene/GaAs Schottky junction photodetector leverages g...In the rapidly evolving field of modern technology,near-infrared(NIR)photodetectors are extremely crucial for efficient and reliable optical communications.The graphene/GaAs Schottky junction photodetector leverages graphene’s exceptional carrier mobility and broadband absorption,coupled with GaAs’s strong absorption in the NIR spectrum,to achieve high responsivity and rapid response times.Here,we present a NIR photodetector employing a graphene/GaAs Schottky junction tailored for communication wavelengths.We fabricated high-performance graphene/GaAs Schottky junction devices with interdigitated electrodes of varying finger widths,systematically investigating their impact on device performance.The experimental results demonstrate that incorporating interdigitated electrodes significantly enhances the collection efficiency of photogenerated carriers in graphene/GaAs photodetectors.When illuminated by 808 nm NIR light at an intensity of 7.23 mW/cm^(2),the device achieves an impressive switch ratio of 10^(7),along with a high responsivity of 40.1 mA/W and a remarkable detectivity of 2.89×10^(13)Jones.Additionally,the device is characterized by rapid response times,with rise and fall times of 18.5 and 17.5μs,respectively,at a 3 dB bandwidth.These findings underscore the significant potential of high-performance graphene/GaAs photodetectors for applications in NIR optoelectronic systems.展开更多
Syndactyly consists of a variable fusion of soft tissue or of bone in adjacent fingers. This has important aesthetic and functional impacts on the development of the child due to the abnormal appearance of the hand. W...Syndactyly consists of a variable fusion of soft tissue or of bone in adjacent fingers. This has important aesthetic and functional impacts on the development of the child due to the abnormal appearance of the hand. When the 1st web space is affected, it compromises grasp and development of the clamp function. Affliction of the 2nd, 3rd or 4th webspaces hinder the independent movement of the fingers adjacent to it. Current syndactyly release techniques have inherent disadvantages such as the use of skin from both the interdigital halves of the syndactylized fingers, the need to skin graft the donor site, postoperative flexion contracture, and need of 2 or more surgical procedures to obtain the desired result. The authors present 7 cases with incomplete simple 2nd, 3rd or 4th webspace syndactylies of multiple etiologies. All cases were treated at the unit of the corresponding author. The flap used in the treatment for all 7 cases did not require skin grafting of the flap donor site and used only skin from one of the fingers, while achieving a webspace dimension similar to normality, with a short recovery period. Furthermore, there were no postoperative finger contractures, diminishing the risk of future relapse.展开更多
A compact interdigital H-mode drift-tube linac (IH-DTL) with the alternating-phase-focusing (APF) method, working at 325 MHz was designed for an injector of a proton medical accelerator. When fed in with a proper RF (...A compact interdigital H-mode drift-tube linac (IH-DTL) with the alternating-phase-focusing (APF) method, working at 325 MHz was designed for an injector of a proton medical accelerator. When fed in with a proper RF (radio frequency) power, the DTL cavity could establish the corresponding electromagnetic field to accelerate the ‘‘proton bunches’’ from an input energy of 3 MeV to an output energy of 7 MeV successfully, without any additional radial focusing elements. The gap-voltage distribution which was obtained from the CST■ Microwave Studio software simulations of the axial electric field was compared with that from the beam dynamics, and the errors met the requirements within ± 5%. In this paper, the RF design procedure and key results of the APF IH-DTL, which include the main RF characteristics of the cavity, frequency sensitivities of the tuners, and coupling factor of the RF power input coupler are presented.展开更多
Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a ...Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a delicate design of the highly wearable embroidered supercapacitors made from the conductive fibers composited.By rendering the conductive interdigitally patterned embroidery as both the current collector and skeleton for the SCs,the novel pseudocapacitive material cobalt phosphides were then successfully electrodeposited,forming the first flexible and wearable in-plane embroidery SCs.The electrochemical measurements manifested that the highest specific capacitance was nearly 156.6 mF cm?2(65.72 F g?1)at the current density of 0.6 mA cm?2(0.25 A g?1),with a high energy density of 0.013 mWh cm?2(5.55 Wh kg?1)at a power density of 0.24 mW cm?2(100 W kg?1).As a demonstration,a monogrammed pattern was ingeniously designed and embroidered on the laboratory gown as the wearable in-plane SCs,which showed both decent electrochemical performance and excellent flexibility.展开更多
We investigate the focusing phenomena of a surface acoustic wave （SAW） field generated by a circular-arc interdigital transducer （IDT） on a piezoelectric crystal. A rigorous vector field theory of surface excitati...We investigate the focusing phenomena of a surface acoustic wave （SAW） field generated by a circular-arc interdigital transducer （IDT） on a piezoelectric crystal. A rigorous vector field theory of surface excitation on the crystal we developed previously is used to evaluate the convergent SAW field instead of the prevalent scalar angular spectrum used in optics. The theoretical results show that the anisotropy of a medium has great impact on the focusing properties of the acoustic beams, such as focal length and symmetrical distributions near the focus. A dark field method is used in experiment to observe the focusing of the SAW tield optically. Although the convergent phenomena of SAW field on the anisotropic media or piezoelectric crystals are very complicated, the experimental data are in agreement with those from the rigorous theory.展开更多
With the principles of microwave circuits and semiconductor device physics,three kinds of microwave power device test circuits are designed and simulated,whose properties are evaluated by a parameter network analyzer ...With the principles of microwave circuits and semiconductor device physics,three kinds of microwave power device test circuits are designed and simulated,whose properties are evaluated by a parameter network analyzer within the frequency range from 3 to 8GHz.The simulated results verify that the test circuit with stepped-impedance filter bias network has a larger bandwidth than that with the radial stub.A microstrip interdigital capacitor is used in the third test circuit to replace the DC block,however,which does not show its advantage during the test frequency band.Based on the simulated results,the stepped-impedance filter test circuit can be used to evaluate microwave power devices in the whole C band,namely from 4 to 8GHz.展开更多
The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were perform...The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were performed at room temperature for frequencies 100 Hz,1 kHz and 10 kHz.It is shown that there is a linear relationship between the capacitance and the concentration of chlorine gas.Influences of the measurement frequency and film thickness of silicate on the sensitivity of the sensor to C12 gas were discussed.And organically modified N,N-diethylaminopropyl-trimethoxysilane (APMS) had a much higher sensitivity.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.
基金This project is supported by National Natural Science Foundation of China (No. 60404017)Municipal Natural Science Foundation of Beijing, China (No.4052008)Plan of Excellent People Cultivation of Beijing, China (No. 20051D0501506)
文摘Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative distribution of the in-plane and out-of-plane displacement of the mode across the thickness of the plate will determine the sensitivity of the mode to a particular loading condition. By considering the dispersion and multi-mode characteristics of guided waves, an interdigital polyvi- nylidene fluoride （PVDF） transducer is designed to realize the mode selection of gnided waves, and a single a0 mode is used for guided wave detection. Fouling detection experiments are conducted in the laboratory using epoxy adhesive on a thin plate. Using the interdigital PVDF transducer, three fouled areas are detected. Using one of the time-frequency analysis methods, the waveforms are further processed. This also demonstrates the validity of this method of fouling detection.
基金The authors are grateful for the support provided by the National Natural Science Foundation of China(Grant No.11772245).
文摘The electro-mechanical coupling behaviors of ferroelectric devices with interdigital electrodes may become complicated due to the material inhomogeneity and local field concentration under the complex working conditions.In this paper,a ferroelectric model,drawn from the typical interdigital electrode structure of a ferroelectric sensor,is established based on phase field theory,to study the polarization evolution and explore the evolution laws in ferroelectrics.Numerical results show that there appears ferroelectric creep even under an applied electric field below the coercive field value.Also,the configurational force theory is introduced to investigate the mechanical behaviors related to polarization switching in the ferroelectric samples with interdigital electrodes.It is found that configurational force and polarization have similar evolution laws in both time evolving and space distribution.And considering the configurational force as the driving force,it is possible to predict the potential direction of polarization evolution and explore its evolution mechanism in ferroelectrics,demonstrating the configurational force as a useful parameter for describing mechanical behavior during the polarization evolution and a powerful tool for investigating the evolution mechanism of microstructure with coupling effects in ferroelectric materials.
基金financial support from the National Natural Science Foundation of China(NSFC)(22109009)the China Postdoctoral Science Foundation(2020M680376)+2 种基金the National Key R&D Program of China(2017YFB1104300)the NSFC(21975027,22035005,52073159)the NSFC-STINT(21911530143)。
文摘Currently,the increasing demands for portable,implantable,and wearable electronics have triggered the interest in miniaturized energy storage devices.Different from conventional energy storage devices,interdigital microbatteries(IMBs) are free of separators and prepared on a single substrate,potentially achieving a short ionic diffusion path and better performance.Meanwhile,they can be easily fabricated and integrated into on-chip miniaturized electronics,holding the promise to provide long-lasting power for advanced microelectronic devices.To date,while many seminal works have been reviewed the topic of microbatteries,there is no work that systematically summarizes the development of IMBs of high energy density and stable voltage platforms from fabrication,functionalization to integration.The current review focuses on the most recent progress in IMBs,discussing advanced micromachining techniques with compatible features to construct high-performance IMBs with smart functions and intelligent integrated systems.The future opportunities and challenges of IMBs are also highlighted,calling for more efforts in this dynamic and fast-growing research field.
基金Project supported by the National Natural Science Foundation of China(No.52075484)the Zhejiang Provincial Funds for Distinguished Young Scientists of China(No.LR19E050001)the Fund for Creative Research Groups of National Natural Science Foundation of China(No.51821093)。
文摘Polymer-based materials with patterned functional particles have been used to develop smart devices with multiple functionalities.This paper presents a novel method to pattern microscale particles into biocompatible polyethylene glycol diacrylate(PEGDA)fluid through a designed surface acoustic wave(SAW)device with slanted-finger interdigital transducers(SFITs).By applying signals of different frequencies,the SFITs can excite SAWs with various wavelengths to pattern the microscale particles.The structural design and working principle of the SAW device with SFITs are firstly presented.To investigate the generation of standing SAWs and pressure field distributions of the SAW device with SFITs,a numerical model was developed.Simulation results showed that different strip-shape patterned pressure fields can be generated,and the period and width of adjacent strips can be adjusted by changing the frequencies of the excitation signals.Experiments were performed to verify that the microscale particles in the PEGDA solution can be successfully patterned into strip-shape patterns with various positions,periods,and widths.The results obtained in this study demonstrate that the developed method of using an SAW device with SFITs can be used for tunable patterning of microscale particles in solutions,and shows great potential for biomedical and microfluidic applications.
基金supported by the Science and Technology Commission of Shanghai Municipality(Nos.18411969700 and 20Y11905600)the Shanghai Municipal Health Commission(Nos.20194Y0337 and 201940476).
文摘Objective:Interdigital infection,as a neglected disease,is frequently misdiagnosed as simple tinea pedis which caused by purely dermatophyte induced.It remains intractable to treatments because of high recurrence rates and potential complications.However,the optimal diagnosis and treatment regimens have not been firmly established.This study aimed to investigate the presentation,etiology,predisposing factors,occurrence regularity,and therapeutic approaches of interdigital infection in Shanghai,China.Methods:A cross-sectional study was conducted at Shanghai Dermatology Hospital in 2019,and data from 57 patients with acute interdigital inflammation were collected.Clinical features and medical histories including blood,bacterial,and mycological examination,culture test,drug susceptibility test results,and follow-up data were analyzed for pathogenic agents.Patients received etiological therapy and were followed up for 1 year.McNemar’s tests were used for comparison of positive rates of direct microscopy and cultures.Results:We found Pseudomonas aeruginosa(40.35%),Staphylococcus aureus(36.84%),and other bacteria(22.80%).The rate of positive fungus culture after bacterial infection recovery was significantly higher than that at the first visit(86.67%vs.36.00%,P=0.001).Compared to other bacteria,Pseudomonas aeruginosa interdigital infection was more inclined to co-infect with fungal agents and was frequently seen in spring and autumn and in patients aged 60-69 years.Interdigital infection caused by Staphylococcus aureus occurred more frequently in the summer and in patients aged 31-40 years.We found that levofloxacin had excellent therapeutic effects for interdigital infection.Conclusion:Our findings may provide important information for establishing diagnostic guidelines and effective treatment,and subsequently,help reduce the rate of recurrence and improve patient outcomes following interdigital infection.
基金supported by the National Natural Science Foundation of China(62474192,62201567)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022048,2022117)the State Key Laboratory of Dynamic Test,which is jointly established by the Province and Ministry,under Open Fund(2022SYSJJ-07)。
文摘This work proposes a fabrication technique that can achieve wafer-level preparation of flexible interdigital electrodes(IDEs)with high-density and large-thickness(HD<).Utilizing these HD< flexible IDEs,we developed a flexible humidity sensor that employs a composite material made of nanowire bundles with carbon quantum dots(CQDBs)for humidity sensitivity.In this device,the composite material facilitates high absorption and capillary condensation of water molecules across various relative humidity(RH)conditions,while the HD< IDEs enhance the effective sensing area.Consequently,we achieve a flexible humidity sensor with exceptional performance.This sensor not only boasts key attributes such as low cost,easy fabrication,and straightforward operation but also establishes a foundation for extensive humidity sensing applications.In comparison to other devices utilizing small-thickness and low-density IDEs,our sensor demonstrates remarkable 2.5-fold and 5.8-fold increase in sensitivity across humidity ranges of 7%-59%RH and 59%-97%RH,respectively.To explore the practical applications of the device,we demonstrate its functionality in diaper humidity detection.With characteristics of wearability and durability,the sensor shows significant potential for humidity monitoring in wearable electronics.
基金supported by the Natural Science Foundation of the Fujian Province,China(2024J010016)the National Key R&D Program of China(2021YFB3600400)the Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Project(2020ZZ113,2021ZZ130)。
文摘Alternating current(AC)driven quantum dots(QDs)light-emitting diodes have attracted widespread attention due to their unique optoelectronic performance.An ACdriven device with an interdigital electrode structure is proposed.The devices exhibit AC electroluminescence(EL)with driving frequency and different frequency responses due to the introduction of P(VDF-TrFE-CFE).The optical and electrical characteristics of the device under various applied voltages and driving frequencies are studied.Unlike the conventional driving mode where carriers are continuously injected into the device,the carriers undergo periodic motion under an AC field.Therefore,there exists an optimal driving frequency that maximizes the EL intensity of the device.Based on the experimental results,the operational mechanism of the device is analyzed,and a carrier transport model is proposed to elucidate the underlying factors contributing to the presence of an optimal driving frequency.Moreover,a model for the device is proposed and its accuracy is verified.From a circuit perspective,the EL behavior of devices at various driving frequencies is analyzed,thereby further confirming the accuracy of the proposed device working mechanism.We believe the work can provide guidance for obtaining advanced QD-based lightemitting technology.
基金This work was financially supported by the 2023 Shaanxi College Students Innovation and Entrepreneur-Ship Training Program Project(S202311664066)supported by the Xi'an Science and Technology Association Youth Talent Lifting Program Project(959202313012).
文摘The application of frequency selection surfaces(FSSs)is limited by large area,narrow bandwidth,low stopband inhibition and large ripple in the passband.A method for designing high-order wide band miniaturized-element frequency selective surface(MEFSS)with capacitance loading is introduced.The proposed structure is composed of multiply sub-wavelength interdigital capacitance layer,sub-wavelength inductive wire grids separated by dielectric substrates.A simple equivalent circuit model,composed of short transmission lines coupled together with shunt inductors and capacitors,is presented for this structure.Using the equivalent circuit model and electromagnetic(EM)model,an analytical synthesis procedure is developed that can be used to synthesize the MEFSS from its desired system-level performance indicators such as the center frequency of operation,bandwidth and stopband inhibition.Using this synthesis procedure,a prototype of the proposed MEFSS with a third-order bandpass response,center frequency of 2.75 GHz,fractional bandwidth of 8%is designed,fabricated,and measured.The measurement results confirm the theoretical predictions and the design procedure of the structure and demonstrate that the proposed MEFSS has a stable frequency response with respect to the angle of incidence of the EM wave in the±30°range incidence,and the in-band return loss is greater than 18 dB,and the rejection in the stopband is greater than 25 dB at the frequency of 3.2 GHz.
基金supported by the Air Force Office of Scientific Research (Grant No. FA9550-10-1-0136)NASA (Grant No. 242026-1BBX11AQ36A)+1 种基金supported by a University of Arkansas Honors College Undergraduate Research grantthe Microelectronics–Photonics program at the University of Arkansas for the COMSOL license
文摘Metal-semiconductor-metal photodetectors on semi-insulating Ga As with interdigital electrodes showed significant enhancement in the spectral response in the near-infrared region as the electrode spacing is reduced. The photocurrent for the device with 5 μm interdigital spacing is five orders of magnitude higher than the dark current, and the room temperature detectivity is on the order of 2.4 × 1012cm Hz1∕2W-1at 5 V bias. Furthermore,the spectral response of this device possesses strong dependence on the polarization of incident light showing potential plasmonic effects with only microscale dimensions. These experimental data were analyzed using optical simulation to confirm the response of the devices.
基金supported by the National Natural Science Foundation of China(62375279)Suzhou Industrial Science and Technology Program(SYG202340,SJC2023004)Distinguished Young Scholar Fund of Natural Science Foundation of Jiangsu Province(BK20240125).
文摘In the rapidly evolving field of modern technology,near-infrared(NIR)photodetectors are extremely crucial for efficient and reliable optical communications.The graphene/GaAs Schottky junction photodetector leverages graphene’s exceptional carrier mobility and broadband absorption,coupled with GaAs’s strong absorption in the NIR spectrum,to achieve high responsivity and rapid response times.Here,we present a NIR photodetector employing a graphene/GaAs Schottky junction tailored for communication wavelengths.We fabricated high-performance graphene/GaAs Schottky junction devices with interdigitated electrodes of varying finger widths,systematically investigating their impact on device performance.The experimental results demonstrate that incorporating interdigitated electrodes significantly enhances the collection efficiency of photogenerated carriers in graphene/GaAs photodetectors.When illuminated by 808 nm NIR light at an intensity of 7.23 mW/cm^(2),the device achieves an impressive switch ratio of 10^(7),along with a high responsivity of 40.1 mA/W and a remarkable detectivity of 2.89×10^(13)Jones.Additionally,the device is characterized by rapid response times,with rise and fall times of 18.5 and 17.5μs,respectively,at a 3 dB bandwidth.These findings underscore the significant potential of high-performance graphene/GaAs photodetectors for applications in NIR optoelectronic systems.
文摘Syndactyly consists of a variable fusion of soft tissue or of bone in adjacent fingers. This has important aesthetic and functional impacts on the development of the child due to the abnormal appearance of the hand. When the 1st web space is affected, it compromises grasp and development of the clamp function. Affliction of the 2nd, 3rd or 4th webspaces hinder the independent movement of the fingers adjacent to it. Current syndactyly release techniques have inherent disadvantages such as the use of skin from both the interdigital halves of the syndactylized fingers, the need to skin graft the donor site, postoperative flexion contracture, and need of 2 or more surgical procedures to obtain the desired result. The authors present 7 cases with incomplete simple 2nd, 3rd or 4th webspace syndactylies of multiple etiologies. All cases were treated at the unit of the corresponding author. The flap used in the treatment for all 7 cases did not require skin grafting of the flap donor site and used only skin from one of the fingers, while achieving a webspace dimension similar to normality, with a short recovery period. Furthermore, there were no postoperative finger contractures, diminishing the risk of future relapse.
基金supported by the National Key Research and Development Program of China(No.2016YFC0105408)
文摘A compact interdigital H-mode drift-tube linac (IH-DTL) with the alternating-phase-focusing (APF) method, working at 325 MHz was designed for an injector of a proton medical accelerator. When fed in with a proper RF (radio frequency) power, the DTL cavity could establish the corresponding electromagnetic field to accelerate the ‘‘proton bunches’’ from an input energy of 3 MeV to an output energy of 7 MeV successfully, without any additional radial focusing elements. The gap-voltage distribution which was obtained from the CST■ Microwave Studio software simulations of the axial electric field was compared with that from the beam dynamics, and the errors met the requirements within ± 5%. In this paper, the RF design procedure and key results of the APF IH-DTL, which include the main RF characteristics of the cavity, frequency sensitivities of the tuners, and coupling factor of the RF power input coupler are presented.
基金The Hong Kong Polytechnic University for the funding support(Nos.1-YW1B,G-YBV2,and G-UACC).
文摘Wearable supercapacitors(SCs)are gaining prominence as portable energy storage devices.To develop high-performance wearable SCs,the significant relationship among material,structure,and performance inspired us with a delicate design of the highly wearable embroidered supercapacitors made from the conductive fibers composited.By rendering the conductive interdigitally patterned embroidery as both the current collector and skeleton for the SCs,the novel pseudocapacitive material cobalt phosphides were then successfully electrodeposited,forming the first flexible and wearable in-plane embroidery SCs.The electrochemical measurements manifested that the highest specific capacitance was nearly 156.6 mF cm?2(65.72 F g?1)at the current density of 0.6 mA cm?2(0.25 A g?1),with a high energy density of 0.013 mWh cm?2(5.55 Wh kg?1)at a power density of 0.24 mW cm?2(100 W kg?1).As a demonstration,a monogrammed pattern was ingeniously designed and embroidered on the laboratory gown as the wearable in-plane SCs,which showed both decent electrochemical performance and excellent flexibility.
基金Supported by the National Natural Science Foundation of China under Grant No 10134020.
文摘We investigate the focusing phenomena of a surface acoustic wave （SAW） field generated by a circular-arc interdigital transducer （IDT） on a piezoelectric crystal. A rigorous vector field theory of surface excitation on the crystal we developed previously is used to evaluate the convergent SAW field instead of the prevalent scalar angular spectrum used in optics. The theoretical results show that the anisotropy of a medium has great impact on the focusing properties of the acoustic beams, such as focal length and symmetrical distributions near the focus. A dark field method is used in experiment to observe the focusing of the SAW tield optically. Although the convergent phenomena of SAW field on the anisotropic media or piezoelectric crystals are very complicated, the experimental data are in agreement with those from the rigorous theory.
文摘With the principles of microwave circuits and semiconductor device physics,three kinds of microwave power device test circuits are designed and simulated,whose properties are evaluated by a parameter network analyzer within the frequency range from 3 to 8GHz.The simulated results verify that the test circuit with stepped-impedance filter bias network has a larger bandwidth than that with the radial stub.A microstrip interdigital capacitor is used in the third test circuit to replace the DC block,however,which does not show its advantage during the test frequency band.Based on the simulated results,the stepped-impedance filter test circuit can be used to evaluate microwave power devices in the whole C band,namely from 4 to 8GHz.
文摘The Cl2-sensitive heteropolysiloxanes(HPS) film was formed on the interdigital capacitor based on silicon dioxide by means of sol-gel process and spin-on technique.Measurements of interdigital capacitance were performed at room temperature for frequencies 100 Hz,1 kHz and 10 kHz.It is shown that there is a linear relationship between the capacitance and the concentration of chlorine gas.Influences of the measurement frequency and film thickness of silicate on the sensitivity of the sensor to C12 gas were discussed.And organically modified N,N-diethylaminopropyl-trimethoxysilane (APMS) had a much higher sensitivity.
