Gravimetric resonant-inspired biosensors have attracted increasing attention in industrial and point-ofcare applications,enabling label-free detection of biomarkers such as DNA and antibodies.Capacitive micromachined ...Gravimetric resonant-inspired biosensors have attracted increasing attention in industrial and point-ofcare applications,enabling label-free detection of biomarkers such as DNA and antibodies.Capacitive micromachined ultrasonic transducers(CMUTs)are promising tools for developing miniaturized highperformance biosensing complementary metal–oxide–silicon(CMOS)platforms.However,their operability is limited by inefficient functionalization,aggregation,crosstalk in the buffer,and the requirement for an external high-voltage(HV)power supply.In this study,we aimed to propose a CMUTs-based resonant biosensor integrated with a CMOS front–end interface coupled with ethylene–glycol alkanethiols to detect single-stranded DNA oligonucleotides with large specificity.The topography of the functionalized surface was characterized by energy-dispersive X-ray microanalysis.Improved selectivity for onchip hybridization was demonstrated by comparing complementary and non-complementary singlestranded DNA oligonucleotides using fluorescence imaging technology.The sensor array was further characterized using a five-element lumped equivalent model.The 4 mm^(2) application-specific integrated circuit chip was designed and developed through 0.18 lm HV bipolar-CMOS-double diffused metal–oxide–silicon(DMOS)technology(BCD)to generate on-chip 20 V HV boosting and to track feedback frequency under a standard 1.8 V supply,with a total power consumption of 3.8 mW in a continuous mode.The measured results indicated a detection sensitivity of 7.943×10^(-3) lmol·L^(-1)·Hz^(-1) over a concentration range of 1 to 100 lmol·L^(-1).In conclusion,the label-free biosensing of DNA under dry conditions was successfully demonstrated using a microfabricated CMUT array with a 2 MHz frequency on CMOS electronics with an internal HV supplier.Moreover,ethylene–glycol alkanethiols successfully deposited self-assembled monolayers on aluminum electrodes,which has never been attempted thus far on CMUTs,to enhance the selectivity of bio-functionalization.The findings of this study indicate the possibility of full-on-chip DNA biosensing with CMUTs.展开更多
Existing microfabricated atomic vapor cells have only one optical channel,which is insufficient for supporting the multiple orthogonal beams required by atomic devices.In this study,we present a novel wafer-level manu...Existing microfabricated atomic vapor cells have only one optical channel,which is insufficient for supporting the multiple orthogonal beams required by atomic devices.In this study,we present a novel wafer-level manufacturing process for fabricating multi-optical-channel atomic vapor cells and an innovative method for batch processing the inner sidewalls of millimeter glass holes to meet optical channel requirements.Surface characterization and transmittance tests demonstrate that the processed inner sidewalls satisfy the criteria for an optical channel.In addition,the construction of an integrated processing platform enables multilayer non-isothermal anode bonding,the filling of inert gases,and the recovery and recycling of noble gases.Measurements of the absorption spectra and free-induction decay signals of xenon-129(^(129)Xe)and xenon-131(^(131)Xe)under different pump-probe schemes demonstrate the suitability of our vapor cell for use in atomic devices including atomic gyroscopes,dual-beam atomic magnetometers,and other optical/atomic devices.The proposed micromolding technology has broad application prospects in the field of optical-device processing.展开更多
Objective:We investigated the correlations between cyclin-dependent kinase 4/6(CDK4/6)levels and human papillomavirus(HPV)infection state in head and neck squamous cell cancer(HNSCC).The aim was to explore the potenti...Objective:We investigated the correlations between cyclin-dependent kinase 4/6(CDK4/6)levels and human papillomavirus(HPV)infection state in head and neck squamous cell cancer(HNSCC).The aim was to explore the potential value of CDK4/6 inhibitors in the treatment of HNSCC.Methods:Multiomic sequencing data for HNSCC were obtained from The Cancer Genome Atlas(TCGA),and the mRNA levels and copy number variations(CNVs)of CDK4 and CDK6 were strictly analyzed.Overall survival(OS)curves were produced using the Kaplan-Meier method,and survival differences between groups were assessed by the log-rank test.Next,gene set enrichment analysis(GSEA)was applied to interrogate CDK4/6-associated molecular pathways in HPV-positive(HPV+)and HPV-negative(HPV-)HNSCC.Last,lymphoid cell infiltrates in each type of HNSCC were explored,and the correlations between CDK4/6 expression and lymphoid infiltrates were explored by Tumor Immune Estimation Resource(TIMER)analysis.Results:Overexpression of either CDK6 or CDK4 was not a relevant factor for OS in HPV-HNSCC(CDK6:top 40%vs.bottom 40%,P=0.885;CDK4:top 40%vs.bottom 40%,P=0.267).In HPV+HNSCC,CDK6 but not CDK4 was a relevant factor for OS(CDK6:top 40%vs.bottom 40%,P=0.002;CDK4:top 40%vs.bottom 40%,P=0.452).GSEA found that overexpressed CDK6 in HPV+HNSCC inhibited pathways involved in the tumor immune response,suggesting its roles in antitumor immunity.TIMER analysis results revealed that CDK6 but not CDK4 accumulation was negatively correlated with the number of tumor-infiltrating lymphocytes specific for HPV+HNSCC,which led to tumor response suppression.Conclusions:CDK6,but not CDK4,is a poor prognostic marker specific in HPV+HNSCC patients.Overexpressed CDK6 might stimulate tumor progression by suppressing lymphocytes infiltration independent of its kinase activity.Only abrogating its kinase activity using current CDK4/6 inhibitors was not enough to block its tumor promotion function.展开更多
In order to fulfill the complex cognitive behaviors in neuromorphic systems with reduced peripheral circuits,the reliable electronic synapses mimicked by single device that achieves diverse long-term and short-term pl...In order to fulfill the complex cognitive behaviors in neuromorphic systems with reduced peripheral circuits,the reliable electronic synapses mimicked by single device that achieves diverse long-term and short-term plasticity are essential.Phase change random access memory(PCRAM)is of great potential for artificial synapses,which faces,however,difficulty to realize short-term plasticity due to the long-lasting resistance drift.This work reports the ruthenium-doped Ge_(2)Sb_(2)Te_(5)(RuGST)based PCRAM,demonstrating a series of synaptic behaviors of short-term potentiation,pair-pulse facilitation,longterm depression,and short-term plasticity in the same single device.The optimized RuGST electronic synapse with the high transformation temperature of hexagonal phase>380C,the outstanding endurance>108 cycles,the low resistance drift factor of 0.092,as well as the extremely high linearity with correlation coefficients of 0.999 and 0.976 in parts of potentiation and depression.Further investigations also go insight to mechanisms of Ru doping according to thorough microstructure characterization,revealing that Ru dopant is able to enter GST lattices thus changing and stabilizing atomic arrangement of GST.This leads to the short-term plasticity realized by RuGST PCRAM.Eventually,the proposed RuGST electronic synapses performs a high accuracy of94.1%in a task of image recognition of CIFAR-100 database using ResNet 101.This work promotes the development of PCRAM platforms for large-scale neuromorphic systems.展开更多
With the rapid development of various fields,including aerospace,industrial measurement and control,and medical monitoring,the need to quantify flow velocity measurements is increasing.It is difficult for traditional ...With the rapid development of various fields,including aerospace,industrial measurement and control,and medical monitoring,the need to quantify flow velocity measurements is increasing.It is difficult for traditional flow velocity sensors to fulfill accuracy requirements for velocity measurements due to their small ranges,susceptibility to environmental impacts,and instability.Herein,to optimize sensor performance,a flexible microelectromechanical system(MEMS)thermal flow sensor is proposed that combines the working principles of thermal loss and thermal temperature difference and utilizes a flexible cavity substrate made of a low-thermal-conductivity polyimide/SiO_(2)(PI/SiO_(2))composite porous film to broaden the measurement range and improve the sensitivity.The measurement results show that the maximum measurable flow velocity can reach 30 m/s with a resolution of 5.4mm/s.The average sensitivities of the sensor are 59.49 mV/(m s−1)in the medium-to-low wind velocity range of 0–2 m/s and 467.31 mV/(m s^(−1))in the wind velocity range of 2–30 m/s.The sensor proposed in this work can enable new applications of flexible flow sensors and wearable devices.展开更多
Pipe contaminant detection holds considerable importance within various industries,such as the aviation,maritime,medicine,and other pertinent fields.This capability is beneficial for forecasting equipment potential fa...Pipe contaminant detection holds considerable importance within various industries,such as the aviation,maritime,medicine,and other pertinent fields.This capability is beneficial for forecasting equipment potential failures,ascertaining operational situations,timely maintenance,and lifespan prediction.However,the majority of existing methods operate offline,and the detectable parameters online are relatively singular.This constraint hampers real-time on-site detection and comprehensive assessments of equipment status.To address these challenges,this paper proposes a sensing method that integrates an ultrasonic unit and an electromagnetic inductive unit for the real-time detection of diverse contaminants and flow rates within a pipeline.The ultrasonic unit comprises a flexible transducer patch fabricated through micromachining technology,which can not only make installation easier but also focus the sound field.Moreover,the sensing unit incorporates three symmetrical solenoid coils.Through a comprehensive analysis of ultrasonic and induction signals,the proposed method can be used to effectively discriminate magnetic metal particles(e.g.,iron),nonmagnetic metal particles(e.g.,copper),nonmetallic particles(e.g.,ceramics),and bubbles.This inclusive categorization encompasses nearly all types of contaminants that may be present in a pipeline.Furthermore,the fluid velocity can be determined through the ultrasonic Doppler frequency shift.The efficacy of the proposed detection principle has been validated by mathematical models and finite element simulations.Various contaminants with diverse velocities were systematically tested within a 14mm diameter pipe.The experimental results demonstrate that the proposed sensor can effectively detect contaminants within the 0.5−3mm range,accurately distinguish contaminant types,and measure flow velocity.展开更多
Hydraulic technology with smaller sizes and higher reliability trends,including fault prediction and intelligent control,requires high-performance temperature and pressure-integrated sensors.Current designs rely on pl...Hydraulic technology with smaller sizes and higher reliability trends,including fault prediction and intelligent control,requires high-performance temperature and pressure-integrated sensors.Current designs rely on planar wafer-or chip-level integration,which is limited by pressure range,chip size,and low reliability.We propose a small-size temperature/high-pressure integrated sensor via the flip-chip technique.The pressure and temperature units are arranged vertically,and the sensing signals of the two units are integrated into one plane through silicon vias and gold–gold bonding,reducing the lateral size and improving the efficiency of signal transmission.The flip-chip technique ensures a reliable electrical connection.A square diaphragm with rounded corners is designed and optimised with simulation to sense high pressure based on the piezoresistive effect.The temperature sensing unit with a thin-film platinum resistor measures temperature and provides back-end high-precision compensation,which will improve the precision of the pressure unit.The integrated chip is fabricated by MEMS technology and packaged to fabricate the extremely small integrated sensor.The integrated sensor is characterised,and the pressure sensor exhibits a sensitivity and sensitivity drift of 7.97mV/MPa and−0.19%FS in the range of 0–20 MPa and−40 to 120℃.The linearity,hysteresis,repeatability,accuracy,basic error,and zero-time drift are 0.16%FS,0.04%FS,0.06%FS,0.18%FS,±0.23%FS and 0.04%FS,respectively.The measurement error of the temperature sensor and temperature coefficient of resistance is less than±1°C and 3142.997 ppm/℃,respectively.The integrated sensor has broad applicability in fault diagnosis and safety monitoring of high-end equipment such as automobile detection,industrial equipment,and oil drilling platforms.展开更多
The chip-scale hybrid optical pumping spin-exchange relaxation-free(SERF)atomic magnetometer with a single-beam arrangement has prominent applications in biomagnetic measurements because of its outstanding features,in...The chip-scale hybrid optical pumping spin-exchange relaxation-free(SERF)atomic magnetometer with a single-beam arrangement has prominent applications in biomagnetic measurements because of its outstanding features,including ultrahigh sensitivity,an enhanced signal-to-noise ratio,homogeneous spin polarization and a much simpler optical configuration than other devices.In this work,a miniaturized single-beam hybrid optical pumping SERF atomic magnetometer based on a microfabricated atomic vapor cell is demonstrated.Although the optically thin Cs atoms are spinpolarized,the dense Rb atoms determine the experimental results.The enhanced signal strength and narrowed resonance linewidth are experimentally proven,which shows the superiority of the proposed magnetometer scheme.By using a differential detection scheme,we effectively suppress optical noise with an approximate five-fold improvement.Moreover,the cell temperature markedly affects the performance of the magnetometer.We systematically investigate the effects of temperature on the magnetometer parameters.The theoretical basis for these effects is explained in detail.The developed miniaturized magnetometer has an optimal magnetic sensitivity of 20 fT/Hz^(1/2).The presented work provides a foundation for the chip-scale integration of ultrahighly sensitive quantum magnetometers that can be used for forward-looking magnetocardiography(MCG)and magnetoencephalography(MEG)applications.展开更多
With the increasing development of intelligent robots and wearable electronics,the demand for high-performance flexible energy storage devices is drastically increasing.In this study,flexible symmetric microsupercapac...With the increasing development of intelligent robots and wearable electronics,the demand for high-performance flexible energy storage devices is drastically increasing.In this study,flexible symmetric microsupercapacitors(MSCs)that could operate in a wide working voltage window were developed by combining laser-direct-writing graphene(LG)electrodes with a phosphoric acid-nonionic surfactant liquid crystal(PA-NI LC)gel electrolyte.To increase the flexibility and enhance the conformal ability of the MSC devices to anisotropic surfaces,after the interdigitated LG formed on the polyimide(PI)film surface,the devices were further transferred onto a flexible,stretchable and transparent polydimethylsiloxane(PDMS)substrate;this substrate displayed favorable flexibility and mechanical characteristics in the bending test.Furthermore,the electrochemical performances of the symmetric MSCs with various electrode widths(300,400,500 and 600μm)were evaluated.The findings revealed that symmetric MSC devices could operate in a large voltage range(0–1.5 V);additionally,the device with a 300μm electrode width(MSC-300)exhibited the largest areal capacitance of 2.3 mF cm^(−2)at 0.07 mA cm^(−2)and an areal(volumetric)energy density of 0.72μWh cm−2(0.36 mWh cm^(−3))at 55.07μWcm−2(27.54mWcm−3),along with favorable mechanical and cycling stability.After charging for~20 s,two MSC-300 devices connected in series could supply energy to a calculator to operate for~130 s,showing its practical application potential as an energy storage device.Moreover,the device displayed favorable reversibility,stability and durability.After 12 months of aging in air at room temperature,its electrochemical performance was not altered,and after charging-discharging measurements for 5000 cycles at 0.07 mA cm^(−2),~93.6%of the areal capacitance was still retained;these results demonstrated its practical long-term application potential as an energy storage device.展开更多
To the editor:Since the onset of COVID-19,several new treatments have been studied,but only a few have received approval for clinical use.However,a challenge we still face is that in real-world medical practice,the pa...To the editor:Since the onset of COVID-19,several new treatments have been studied,but only a few have received approval for clinical use.However,a challenge we still face is that in real-world medical practice,the patient population may differ from those in clinical trials.For instance,prolonged viral elimination has become an issue in immunocompromised patients[1,2]展开更多
Due to the excellent mechanical,chemical,and electrical properties of third-generation semiconductor silicon carbide(SiC),pressure sensors utilizing this material might be able to operate in extreme environments with ...Due to the excellent mechanical,chemical,and electrical properties of third-generation semiconductor silicon carbide(SiC),pressure sensors utilizing this material might be able to operate in extreme environments with temperatures exceeding 300℃.However,the significant output drift at elevated temperatures challenges the precision and stability of measurements.Real-time in situ temperature monitoring of the pressure sensor chip is highly important for the accurate compensation of the pressure sensor.In this study,we fabricate platinum(Pt)thin-film resistance temperature detectors(RTDs)on a SiC substrate by incorporating aluminum oxide(Al_(2)O_(3))as the transition layer and utilizing aluminum nitride(AIN)grooves for alignment through microfabrication techniques.The composite layers strongly adhere to the substrate at temperatures reaching 950℃,and the interface of the Al2O3/Pt bilayer remains stable at elevated temperatures of approximately 950 C.This stability contributes to the excellent high-temperature electrical performance of the Pt RTD,enabling it to endure temperatures exceeding 850℃ with good linearity.These characteristics establish a basis for the future integration of Pt RTD in SiC pressure sensors.Furthermore,tests and analyses are conducted on the interfacial diffusion,surface morphological,microstructural,and electrical properties of the Pt flms at various annealing temperatures.It can be inferred that the tensile stress and self-diffusion of Pt films lead to the formation of hillocks,ultimately reducing the electrical performance of the Pt thin-flm RTD.To increase the upper temperature threshold,steps should be taken to prevent the agglomeration of Pt films.展开更多
Recently, considerable attention in the field of cancer therapy has been focused on the mammalian rapamycin target(m TOR), inhibition of which could result in autophagic cell death(ACD). Though novel combination chemo...Recently, considerable attention in the field of cancer therapy has been focused on the mammalian rapamycin target(m TOR), inhibition of which could result in autophagic cell death(ACD). Though novel combination chemotherapy of autophagy inducers with chemotherapeutic agents is extensively investigated, nanomedicine-based combination therapy for ACD remains in infancy. In attempt to actively trigger ACD for synergistic chemotherapy, here we incorporated autophagy inducer rapamycin(RAP) into 7 pep-modified PEG-DSPE polymer micelles(7 pep-M-RAP) to specifically target and efficiently priming ACD of MCF-7 human breast cancer cells with high expression of transferrin receptor(Tf R). Cytotoxic paclitaxel(PTX)-loaded micelle(7 pep-M-PTX) was regarded as chemotherapeutic drug model. We discovered that with superior intracellular uptake in vitro and more tumor accumulation of micelles in vivo, 7 pep-M-RAP exhibited excellent autophagy induction and synergistic antitumor efficacy with 7 pep-M-PTX. Mechanism study further revealed that 7 pep-M-RAP and 7 pep-MPTX used in combination provided enhanced efficacy through induction of both apoptosis-and mitochondria-associated autophagic cell death. Together, our findings suggested that the targeted excess autophagy may provide a rational strategy to improve therapeutic outcome of breast cancer, and simultaneous induction of ACD and apoptosis may be a promising anticancer modality.展开更多
Suppose that G is a finite p-group.If all subgroups of index p^(t)of G are abelian and at least one subgroup of index p^(t−1)of G is not abelian,then G is called an A_(t)-group.We useA0-group to denote an abelian grou...Suppose that G is a finite p-group.If all subgroups of index p^(t)of G are abelian and at least one subgroup of index p^(t−1)of G is not abelian,then G is called an A_(t)-group.We useA0-group to denote an abelian group.From the definition,we know every finite non-abelian p-group can be regarded as an A_(t)-group for some positive integer t.A_(1)-groups and A_(2)-groups have been classified.Classifying A_(3)-groups is an old problem.In this paper,some general properties about A_(t)-groups are given.A_(3)-groups are completely classified up to isomorphism.Moreover,we determine the Frattini subgroup,the derived subgroup and the center of every A_(3)-group,and give the number of A_(1)-subgroups and the triple(μ_(0),μ_(1),μ_(2))of every A_(3)-group,whereμi denotes the number of A_(i)-subgroups of index p of A_(3)-groups.展开更多
In this paper,a novel resonant pressure sensor is developed based on electrostatic excitation and piezoresistive detection.The measured pressure applied to the diaphragm will cause the resonant frequency shift of the ...In this paper,a novel resonant pressure sensor is developed based on electrostatic excitation and piezoresistive detection.The measured pressure applied to the diaphragm will cause the resonant frequency shift of the resonator.The working mode stress–frequency theory of a double-ended tuning fork with an enhanced coupling beam is proposed,which is compatible with the simulation and experiment.A unique piezoresistive detection method based on small axially deformed beams with a resonant status is proposed,and other adjacent mode outputs are easily shielded.According to the structure design,high-vacuum wafer-level packaging with different doping in the anodic bonding interface is fabricated to ensure the high quality of the resonator.The pressure sensor chip is fabricated by dry/wet etching,high-temperature silicon bonding,ion implantation,and wafer-level anodic bonding.The results show that the fabricated sensor has a measuring sensitivity of~19 Hz/kPa and a nonlinearity of 0.02%full scale in the pressure range of 0–200 kPa at a full temperature range of−40 to 80°C.The sensor also shows a good quality factor>25,000,which demonstrates the good vacuum performance.Thus,the feasibility of the design is a commendable solution for high-accuracy pressure measurements.展开更多
Pressure sensors play a vital role in aerospace,automotive,medical,and consumer electronics.Although microelectromechanical system(MEMS)-based pressure sensors have been widely used for decades,new trends in pressure ...Pressure sensors play a vital role in aerospace,automotive,medical,and consumer electronics.Although microelectromechanical system(MEMS)-based pressure sensors have been widely used for decades,new trends in pressure sensors,including higher sensitivity,higher accuracy,better multifunctionality,smaller chip size,and smaller package size,have recently emerged.The demand for performance upgradation has led to breakthroughs in sensor materials,design,fabrication,and packaging methods,which have emerged frequently in recent decades.This paper reviews common new trends in MEMS pressure sensors,including minute differential pressure sensors(MDPSs),resonant pressure sensors(RPSs),integrated pressure sensors,miniaturized pressure chips,and leadless pressure sensors.To realize an extremely sensitive MDPS with broad application potential,including in medical ventilators and fire residual pressure monitors,the“beam-membrane-island”sensor design exhibits the best performance of 66μV/V/kPa with a natural frequency of 11.3 kHz.In high-accuracy applications,silicon and quartz RPS are analyzed,and both materials show±0.01%FS accuracy with respect to varying temperature coefficient of frequency(TCF)control methods.To improve MEMS sensor integration,different integrated“pressure+x”sensor designs and fabrication methods are compared.In this realm,the intercoupling effect still requires further investigation.Typical fabrication methods for microsized pressure sensor chips are also reviewed.To date,the chip thickness size can be controlled to be<0.1 mm,which is advantageous for implant sensors.Furthermore,a leadless pressure sensor was analyzed,offering an extremely small package size and harsh environmental compatibility.This review is structured as follows.The background of pressure sensors is first presented.Then,an in-depth introduction to MEMS pressure sensors based on different application scenarios is provided.Additionally,their respective characteristics and significant advancements are analyzed and summarized.Finally,development trends of MEMS pressure sensors in different fields are analyzed.展开更多
Single-particle tracking photoactivated local- ization microscopy （sptPALM） has recently emerged as a powerful tool for high-density imaging and tracking of individual molecules in living cells. In this work, we hav...Single-particle tracking photoactivated local- ization microscopy （sptPALM） has recently emerged as a powerful tool for high-density imaging and tracking of individual molecules in living cells. In this work, we have monitored and compared the diffusion dynamics of TGF-β type II receptor （TβRII） at high expression level using both traditional single-particle tracking （SPT） and sptPALM. The ligand-induced aggregation of TβRII oligomers was further indicated by sptPALM. Due to the capacity of distinguishing and tracking single molecules within diffraction limit, sptPALM outperforms traditional SPT by providing more accurate biophysical information,展开更多
Highly precise micromanipulation tools that can manipulate and interrogate cell organelles and components must be developed to support the rapid development of new cell-based medical therapies,thereby facilitating in-...Highly precise micromanipulation tools that can manipulate and interrogate cell organelles and components must be developed to support the rapid development of new cell-based medical therapies,thereby facilitating in-depth understanding of cell dynamics,cell component functions,and disease mechanisms.This paper presents a literature review on micro/nanomanipulation tools and their control methods for single-cell surgery.Micromanipulation methods specifically based on laser,microneedle,and untethered micro/nanotools are presented in detail.The limitations of these techniques are also discussed.The biological significance and clinical applications of single-cell surgery are also addressed in this paper.展开更多
Abstract A novel micro-electromechanical systems piezoresistive pressure sensor with a diagonally positioned peninsula-island structure has high sensitivity for ultra- low-pressure measurement. The pressure sensor was...Abstract A novel micro-electromechanical systems piezoresistive pressure sensor with a diagonally positioned peninsula-island structure has high sensitivity for ultra- low-pressure measurement. The pressure sensor was designed with a working range of 0-500 Pa and had a high sensitivity of 0.06 mV-V^-1-Pa-1. The trade-off between high sensitivity and linearity was alleviated. Moreover, the influence of the installation angle on the sensing chip output was analyzed, and an application experiment of the sensor was conducted using the built pipettor test platform. Findings indicated that the proposed pressure sensor had sufficient resolution ability and accuracy to detect the pressure variation in the pipettor chamber. Therefore, the proposed pressure sensor has strong potential for medical equipment application.展开更多
Flexible strain sensors are promising candidates for intelligent wearable devices.Among previous studies,although crack-based sensors have attracted a lot of attention due to their ultrahigh sensitivity,large strain u...Flexible strain sensors are promising candidates for intelligent wearable devices.Among previous studies,although crack-based sensors have attracted a lot of attention due to their ultrahigh sensitivity,large strain usually causes fractures in the conductive paths.Because of the unstable crack structure,the tradeoff between sensitivity and workable strain range is still a challenge.As carbon nanotubes(CNTs)and silver nanowires(AgNWs)can form a strong interface with the thermoplastic substrate and strengthen the conductive network by capillary force during water evaporation,CNTs and AgNWs were deposited on electrospun TPU fiber mats via vacuum-assisted filtration in this work.The prestretching treatment constructed a microcrack structure that endowed the sensor with the combined characteristics of a wide working range(0~171%strain),ultrahigh sensitivity(a gauge factor of 691 within 0~102%strain,~2×10^(4) within 102~135%strain,and>11×10^(4) within 135~171%strain),a fast response time(~65 ms),small hysteresis,and superior durability(>2000 cycles).Subsequently,the sensing mechanism of the sensor was studied.Distributed microcrack propagation based on the“island-bridge”structure was explained in detail,and its influence on the strain-sensing behavior of the sensor was analyzed.Finally,the sensor was assembled to monitor various vibration signals and human motions,demonstrating its potential applications in the fields of electronic skin and human health monitoring.展开更多
基金supported by the National Key Research and Development Program of China(2022YFB3205400)the National Natural Science Foundation of China(52275570)+1 种基金the Postdoctoral Innovation Talents Support Program(BX20230288)the Postdoctoral Science Foundation of Shaanxi Province(2018BSHEDZZ08).
文摘Gravimetric resonant-inspired biosensors have attracted increasing attention in industrial and point-ofcare applications,enabling label-free detection of biomarkers such as DNA and antibodies.Capacitive micromachined ultrasonic transducers(CMUTs)are promising tools for developing miniaturized highperformance biosensing complementary metal–oxide–silicon(CMOS)platforms.However,their operability is limited by inefficient functionalization,aggregation,crosstalk in the buffer,and the requirement for an external high-voltage(HV)power supply.In this study,we aimed to propose a CMUTs-based resonant biosensor integrated with a CMOS front–end interface coupled with ethylene–glycol alkanethiols to detect single-stranded DNA oligonucleotides with large specificity.The topography of the functionalized surface was characterized by energy-dispersive X-ray microanalysis.Improved selectivity for onchip hybridization was demonstrated by comparing complementary and non-complementary singlestranded DNA oligonucleotides using fluorescence imaging technology.The sensor array was further characterized using a five-element lumped equivalent model.The 4 mm^(2) application-specific integrated circuit chip was designed and developed through 0.18 lm HV bipolar-CMOS-double diffused metal–oxide–silicon(DMOS)technology(BCD)to generate on-chip 20 V HV boosting and to track feedback frequency under a standard 1.8 V supply,with a total power consumption of 3.8 mW in a continuous mode.The measured results indicated a detection sensitivity of 7.943×10^(-3) lmol·L^(-1)·Hz^(-1) over a concentration range of 1 to 100 lmol·L^(-1).In conclusion,the label-free biosensing of DNA under dry conditions was successfully demonstrated using a microfabricated CMUT array with a 2 MHz frequency on CMOS electronics with an internal HV supplier.Moreover,ethylene–glycol alkanethiols successfully deposited self-assembled monolayers on aluminum electrodes,which has never been attempted thus far on CMUTs,to enhance the selectivity of bio-functionalization.The findings of this study indicate the possibility of full-on-chip DNA biosensing with CMUTs.
基金supported in part by the National Key Research and Development Plan(2022YFB3203400)the National Natural Science Foundation of China(62103324 and U1909221)the Natural Science Foundation of Shaanxi(2022JQ-554).
文摘Existing microfabricated atomic vapor cells have only one optical channel,which is insufficient for supporting the multiple orthogonal beams required by atomic devices.In this study,we present a novel wafer-level manufacturing process for fabricating multi-optical-channel atomic vapor cells and an innovative method for batch processing the inner sidewalls of millimeter glass holes to meet optical channel requirements.Surface characterization and transmittance tests demonstrate that the processed inner sidewalls satisfy the criteria for an optical channel.In addition,the construction of an integrated processing platform enables multilayer non-isothermal anode bonding,the filling of inert gases,and the recovery and recycling of noble gases.Measurements of the absorption spectra and free-induction decay signals of xenon-129(^(129)Xe)and xenon-131(^(131)Xe)under different pump-probe schemes demonstrate the suitability of our vapor cell for use in atomic devices including atomic gyroscopes,dual-beam atomic magnetometers,and other optical/atomic devices.The proposed micromolding technology has broad application prospects in the field of optical-device processing.
基金supported by the Beijing Municipal Science and Technology Commission (No. Z171100001017127)the Fund for National Natural Science Foundation of China (No. 81472186)
文摘Objective:We investigated the correlations between cyclin-dependent kinase 4/6(CDK4/6)levels and human papillomavirus(HPV)infection state in head and neck squamous cell cancer(HNSCC).The aim was to explore the potential value of CDK4/6 inhibitors in the treatment of HNSCC.Methods:Multiomic sequencing data for HNSCC were obtained from The Cancer Genome Atlas(TCGA),and the mRNA levels and copy number variations(CNVs)of CDK4 and CDK6 were strictly analyzed.Overall survival(OS)curves were produced using the Kaplan-Meier method,and survival differences between groups were assessed by the log-rank test.Next,gene set enrichment analysis(GSEA)was applied to interrogate CDK4/6-associated molecular pathways in HPV-positive(HPV+)and HPV-negative(HPV-)HNSCC.Last,lymphoid cell infiltrates in each type of HNSCC were explored,and the correlations between CDK4/6 expression and lymphoid infiltrates were explored by Tumor Immune Estimation Resource(TIMER)analysis.Results:Overexpression of either CDK6 or CDK4 was not a relevant factor for OS in HPV-HNSCC(CDK6:top 40%vs.bottom 40%,P=0.885;CDK4:top 40%vs.bottom 40%,P=0.267).In HPV+HNSCC,CDK6 but not CDK4 was a relevant factor for OS(CDK6:top 40%vs.bottom 40%,P=0.002;CDK4:top 40%vs.bottom 40%,P=0.452).GSEA found that overexpressed CDK6 in HPV+HNSCC inhibited pathways involved in the tumor immune response,suggesting its roles in antitumor immunity.TIMER analysis results revealed that CDK6 but not CDK4 accumulation was negatively correlated with the number of tumor-infiltrating lymphocytes specific for HPV+HNSCC,which led to tumor response suppression.Conclusions:CDK6,but not CDK4,is a poor prognostic marker specific in HPV+HNSCC patients.Overexpressed CDK6 might stimulate tumor progression by suppressing lymphocytes infiltration independent of its kinase activity.Only abrogating its kinase activity using current CDK4/6 inhibitors was not enough to block its tumor promotion function.
基金supported in part by the National Natural Science Foundation of China(52105589 and U1909221)in part by the China Postdoctoral Science Foundation(2021M692590)+2 种基金in part by the Beijing Advanced Innovation Center for Intelligent Robots and Systems(2019IRS08)in part by the Fundamental Research Funds for the Central Universities(China)(xzy012021009)in part by the State Key Laboratory of Robotics and Systems(HIT)(SKLRS2021KF17)。
基金National Natural Science Foundation of China,Grant/Award Numbers:M0441,61634008,91964204111 Project of China,Grant/Award Number:B14040+3 种基金Open Project of National Key Laboratory of Materials for Integrated Circuits,Grant/Award Number:SKL202207Shanghai Research and Innovation Functional Program,Grant/Award Number:17DZ2260900National Key Projects of China,Grant/Award Number:2021XJTU0016Natural Sciences and Engineering Research Council of Canada,Grant/Award Numbers:RGPIN-2017-06915,RGPIN-2023-04416。
文摘In order to fulfill the complex cognitive behaviors in neuromorphic systems with reduced peripheral circuits,the reliable electronic synapses mimicked by single device that achieves diverse long-term and short-term plasticity are essential.Phase change random access memory(PCRAM)is of great potential for artificial synapses,which faces,however,difficulty to realize short-term plasticity due to the long-lasting resistance drift.This work reports the ruthenium-doped Ge_(2)Sb_(2)Te_(5)(RuGST)based PCRAM,demonstrating a series of synaptic behaviors of short-term potentiation,pair-pulse facilitation,longterm depression,and short-term plasticity in the same single device.The optimized RuGST electronic synapse with the high transformation temperature of hexagonal phase>380C,the outstanding endurance>108 cycles,the low resistance drift factor of 0.092,as well as the extremely high linearity with correlation coefficients of 0.999 and 0.976 in parts of potentiation and depression.Further investigations also go insight to mechanisms of Ru doping according to thorough microstructure characterization,revealing that Ru dopant is able to enter GST lattices thus changing and stabilizing atomic arrangement of GST.This leads to the short-term plasticity realized by RuGST PCRAM.Eventually,the proposed RuGST electronic synapses performs a high accuracy of94.1%in a task of image recognition of CIFAR-100 database using ResNet 101.This work promotes the development of PCRAM platforms for large-scale neuromorphic systems.
基金supported by the National Key Research&Development(R&D)Program of China(grant number 2023YFF0720800)the Shaanxi 2023 Natural Science Basic Research Plan(grant number 2023-JC-QN-0489)+1 种基金the National Natural Science Foundation of China(grant number 52175548)the Free Exploration and Innovation-Teacher Program of Basic Scientific Research Business Expenses of Xi’an Jiaotong University(grant number xzy012023054).
文摘With the rapid development of various fields,including aerospace,industrial measurement and control,and medical monitoring,the need to quantify flow velocity measurements is increasing.It is difficult for traditional flow velocity sensors to fulfill accuracy requirements for velocity measurements due to their small ranges,susceptibility to environmental impacts,and instability.Herein,to optimize sensor performance,a flexible microelectromechanical system(MEMS)thermal flow sensor is proposed that combines the working principles of thermal loss and thermal temperature difference and utilizes a flexible cavity substrate made of a low-thermal-conductivity polyimide/SiO_(2)(PI/SiO_(2))composite porous film to broaden the measurement range and improve the sensitivity.The measurement results show that the maximum measurable flow velocity can reach 30 m/s with a resolution of 5.4mm/s.The average sensitivities of the sensor are 59.49 mV/(m s−1)in the medium-to-low wind velocity range of 0–2 m/s and 467.31 mV/(m s^(−1))in the wind velocity range of 2–30 m/s.The sensor proposed in this work can enable new applications of flexible flow sensors and wearable devices.
基金supported in part by the National Key Research and Development Program(2022YFB3205400)the National Natural Science Foundation of China(52275570)+1 种基金the Major Science and Technology Project of Anhui Province(2022e03020002)the Shaanxi Province Qin Chuangyuan“Scientist+Engineer”Team(2022KXJ-02).
文摘Pipe contaminant detection holds considerable importance within various industries,such as the aviation,maritime,medicine,and other pertinent fields.This capability is beneficial for forecasting equipment potential failures,ascertaining operational situations,timely maintenance,and lifespan prediction.However,the majority of existing methods operate offline,and the detectable parameters online are relatively singular.This constraint hampers real-time on-site detection and comprehensive assessments of equipment status.To address these challenges,this paper proposes a sensing method that integrates an ultrasonic unit and an electromagnetic inductive unit for the real-time detection of diverse contaminants and flow rates within a pipeline.The ultrasonic unit comprises a flexible transducer patch fabricated through micromachining technology,which can not only make installation easier but also focus the sound field.Moreover,the sensing unit incorporates three symmetrical solenoid coils.Through a comprehensive analysis of ultrasonic and induction signals,the proposed method can be used to effectively discriminate magnetic metal particles(e.g.,iron),nonmagnetic metal particles(e.g.,copper),nonmetallic particles(e.g.,ceramics),and bubbles.This inclusive categorization encompasses nearly all types of contaminants that may be present in a pipeline.Furthermore,the fluid velocity can be determined through the ultrasonic Doppler frequency shift.The efficacy of the proposed detection principle has been validated by mathematical models and finite element simulations.Various contaminants with diverse velocities were systematically tested within a 14mm diameter pipe.The experimental results demonstrate that the proposed sensor can effectively detect contaminants within the 0.5−3mm range,accurately distinguish contaminant types,and measure flow velocity.
基金supported in part by the National Key Research&Development(R&D)Plan(2022YFB3205800)the National Natural Science Foundation of China(52305618).
文摘Hydraulic technology with smaller sizes and higher reliability trends,including fault prediction and intelligent control,requires high-performance temperature and pressure-integrated sensors.Current designs rely on planar wafer-or chip-level integration,which is limited by pressure range,chip size,and low reliability.We propose a small-size temperature/high-pressure integrated sensor via the flip-chip technique.The pressure and temperature units are arranged vertically,and the sensing signals of the two units are integrated into one plane through silicon vias and gold–gold bonding,reducing the lateral size and improving the efficiency of signal transmission.The flip-chip technique ensures a reliable electrical connection.A square diaphragm with rounded corners is designed and optimised with simulation to sense high pressure based on the piezoresistive effect.The temperature sensing unit with a thin-film platinum resistor measures temperature and provides back-end high-precision compensation,which will improve the precision of the pressure unit.The integrated chip is fabricated by MEMS technology and packaged to fabricate the extremely small integrated sensor.The integrated sensor is characterised,and the pressure sensor exhibits a sensitivity and sensitivity drift of 7.97mV/MPa and−0.19%FS in the range of 0–20 MPa and−40 to 120℃.The linearity,hysteresis,repeatability,accuracy,basic error,and zero-time drift are 0.16%FS,0.04%FS,0.06%FS,0.18%FS,±0.23%FS and 0.04%FS,respectively.The measurement error of the temperature sensor and temperature coefficient of resistance is less than±1°C and 3142.997 ppm/℃,respectively.The integrated sensor has broad applicability in fault diagnosis and safety monitoring of high-end equipment such as automobile detection,industrial equipment,and oil drilling platforms.
基金supported by the National Key Research&Development(R&D)Program of China(Grant No.2022YFB3203400)the National Natural Science Foundation of China(Grant No.62103324)+1 种基金the National Natural Science Foundation of China(Grant No.52305618)the Chongqing Natural Science Basic Research Project(cstc2021jcyj-msxmX0801).
文摘The chip-scale hybrid optical pumping spin-exchange relaxation-free(SERF)atomic magnetometer with a single-beam arrangement has prominent applications in biomagnetic measurements because of its outstanding features,including ultrahigh sensitivity,an enhanced signal-to-noise ratio,homogeneous spin polarization and a much simpler optical configuration than other devices.In this work,a miniaturized single-beam hybrid optical pumping SERF atomic magnetometer based on a microfabricated atomic vapor cell is demonstrated.Although the optically thin Cs atoms are spinpolarized,the dense Rb atoms determine the experimental results.The enhanced signal strength and narrowed resonance linewidth are experimentally proven,which shows the superiority of the proposed magnetometer scheme.By using a differential detection scheme,we effectively suppress optical noise with an approximate five-fold improvement.Moreover,the cell temperature markedly affects the performance of the magnetometer.We systematically investigate the effects of temperature on the magnetometer parameters.The theoretical basis for these effects is explained in detail.The developed miniaturized magnetometer has an optimal magnetic sensitivity of 20 fT/Hz^(1/2).The presented work provides a foundation for the chip-scale integration of ultrahighly sensitive quantum magnetometers that can be used for forward-looking magnetocardiography(MCG)and magnetoencephalography(MEG)applications.
基金supported by the National Key Research&Development(R&D)Program of China(grant number 2021YFB3203200)the Shaanxi 2023 Natural Science Basic Research Plan(grant number 2023-JC-QN-0489)+1 种基金the National Natural Science Foundation of China(grant number 52175548)the financial support from Shaanxi Province Postdoctoral Research Project Funding,State Key Laboratory for Manufacturing Systems Engineering and Free Exploration and Innovation-Teacher Program of Basic Scientific Research Business Expenses of Xi’an Jiaotong University(xzy012023054).
文摘With the increasing development of intelligent robots and wearable electronics,the demand for high-performance flexible energy storage devices is drastically increasing.In this study,flexible symmetric microsupercapacitors(MSCs)that could operate in a wide working voltage window were developed by combining laser-direct-writing graphene(LG)electrodes with a phosphoric acid-nonionic surfactant liquid crystal(PA-NI LC)gel electrolyte.To increase the flexibility and enhance the conformal ability of the MSC devices to anisotropic surfaces,after the interdigitated LG formed on the polyimide(PI)film surface,the devices were further transferred onto a flexible,stretchable and transparent polydimethylsiloxane(PDMS)substrate;this substrate displayed favorable flexibility and mechanical characteristics in the bending test.Furthermore,the electrochemical performances of the symmetric MSCs with various electrode widths(300,400,500 and 600μm)were evaluated.The findings revealed that symmetric MSC devices could operate in a large voltage range(0–1.5 V);additionally,the device with a 300μm electrode width(MSC-300)exhibited the largest areal capacitance of 2.3 mF cm^(−2)at 0.07 mA cm^(−2)and an areal(volumetric)energy density of 0.72μWh cm−2(0.36 mWh cm^(−3))at 55.07μWcm−2(27.54mWcm−3),along with favorable mechanical and cycling stability.After charging for~20 s,two MSC-300 devices connected in series could supply energy to a calculator to operate for~130 s,showing its practical application potential as an energy storage device.Moreover,the device displayed favorable reversibility,stability and durability.After 12 months of aging in air at room temperature,its electrochemical performance was not altered,and after charging-discharging measurements for 5000 cycles at 0.07 mA cm^(−2),~93.6%of the areal capacitance was still retained;these results demonstrated its practical long-term application potential as an energy storage device.
基金Peking University Third Hospital,BYSYDL2023001-05,BYSYDL2023001-08,BMU2023XY019.
文摘To the editor:Since the onset of COVID-19,several new treatments have been studied,but only a few have received approval for clinical use.However,a challenge we still face is that in real-world medical practice,the patient population may differ from those in clinical trials.For instance,prolonged viral elimination has become an issue in immunocompromised patients[1,2]
基金The authors are thankful for support from the National Natural Science Foundation of China(Nos.52175517 and 51720105016)the Zhejiang Laboratory(2022MGOAB03)+3 种基金the China Postdoctoral Science Foundation(No.2017M610634)the Recruitment Program of Global Experts(Grant No.WQ2017610445)the Innovation Capability Support Program of Shaanxi Province(No.2021TD-23)the China National Postdoctoral Program for Innovative Talents(BX20230289)。
文摘Due to the excellent mechanical,chemical,and electrical properties of third-generation semiconductor silicon carbide(SiC),pressure sensors utilizing this material might be able to operate in extreme environments with temperatures exceeding 300℃.However,the significant output drift at elevated temperatures challenges the precision and stability of measurements.Real-time in situ temperature monitoring of the pressure sensor chip is highly important for the accurate compensation of the pressure sensor.In this study,we fabricate platinum(Pt)thin-film resistance temperature detectors(RTDs)on a SiC substrate by incorporating aluminum oxide(Al_(2)O_(3))as the transition layer and utilizing aluminum nitride(AIN)grooves for alignment through microfabrication techniques.The composite layers strongly adhere to the substrate at temperatures reaching 950℃,and the interface of the Al2O3/Pt bilayer remains stable at elevated temperatures of approximately 950 C.This stability contributes to the excellent high-temperature electrical performance of the Pt RTD,enabling it to endure temperatures exceeding 850℃ with good linearity.These characteristics establish a basis for the future integration of Pt RTD in SiC pressure sensors.Furthermore,tests and analyses are conducted on the interfacial diffusion,surface morphological,microstructural,and electrical properties of the Pt flms at various annealing temperatures.It can be inferred that the tensile stress and self-diffusion of Pt films lead to the formation of hillocks,ultimately reducing the electrical performance of the Pt thin-flm RTD.To increase the upper temperature threshold,steps should be taken to prevent the agglomeration of Pt films.
基金supported by the National Natural Science Foundation of China(81690264)Key Project from the Ministry of Science and Technology(Grant No.2018ZX09721003)Scientific Research Incubation Fund of Beijing Children’s Hospital,Capital Medical University(Grant No.GPY201711,China)
文摘Recently, considerable attention in the field of cancer therapy has been focused on the mammalian rapamycin target(m TOR), inhibition of which could result in autophagic cell death(ACD). Though novel combination chemotherapy of autophagy inducers with chemotherapeutic agents is extensively investigated, nanomedicine-based combination therapy for ACD remains in infancy. In attempt to actively trigger ACD for synergistic chemotherapy, here we incorporated autophagy inducer rapamycin(RAP) into 7 pep-modified PEG-DSPE polymer micelles(7 pep-M-RAP) to specifically target and efficiently priming ACD of MCF-7 human breast cancer cells with high expression of transferrin receptor(Tf R). Cytotoxic paclitaxel(PTX)-loaded micelle(7 pep-M-PTX) was regarded as chemotherapeutic drug model. We discovered that with superior intracellular uptake in vitro and more tumor accumulation of micelles in vivo, 7 pep-M-RAP exhibited excellent autophagy induction and synergistic antitumor efficacy with 7 pep-M-PTX. Mechanism study further revealed that 7 pep-M-RAP and 7 pep-MPTX used in combination provided enhanced efficacy through induction of both apoptosis-and mitochondria-associated autophagic cell death. Together, our findings suggested that the targeted excess autophagy may provide a rational strategy to improve therapeutic outcome of breast cancer, and simultaneous induction of ACD and apoptosis may be a promising anticancer modality.
基金This work was supported by NSFC(Nos.11371232,11471198)by NSF of Shanxi Province(No.2013011001).
文摘Suppose that G is a finite p-group.If all subgroups of index p^(t)of G are abelian and at least one subgroup of index p^(t−1)of G is not abelian,then G is called an A_(t)-group.We useA0-group to denote an abelian group.From the definition,we know every finite non-abelian p-group can be regarded as an A_(t)-group for some positive integer t.A_(1)-groups and A_(2)-groups have been classified.Classifying A_(3)-groups is an old problem.In this paper,some general properties about A_(t)-groups are given.A_(3)-groups are completely classified up to isomorphism.Moreover,we determine the Frattini subgroup,the derived subgroup and the center of every A_(3)-group,and give the number of A_(1)-subgroups and the triple(μ_(0),μ_(1),μ_(2))of every A_(3)-group,whereμi denotes the number of A_(i)-subgroups of index p of A_(3)-groups.
基金This work was supported in part by the National Natural Science Foundation of China(Grant Nos.51890884,51421004,and 91748207)the Key Research and Development Project of Shaanxi Province(Grant No.2018ZDCXL-GY-02-02)+1 种基金the Shaanxi Province Natural Science Basic Research Project(2019JC-06)the 111 Program(Grant No.B12016).
文摘In this paper,a novel resonant pressure sensor is developed based on electrostatic excitation and piezoresistive detection.The measured pressure applied to the diaphragm will cause the resonant frequency shift of the resonator.The working mode stress–frequency theory of a double-ended tuning fork with an enhanced coupling beam is proposed,which is compatible with the simulation and experiment.A unique piezoresistive detection method based on small axially deformed beams with a resonant status is proposed,and other adjacent mode outputs are easily shielded.According to the structure design,high-vacuum wafer-level packaging with different doping in the anodic bonding interface is fabricated to ensure the high quality of the resonator.The pressure sensor chip is fabricated by dry/wet etching,high-temperature silicon bonding,ion implantation,and wafer-level anodic bonding.The results show that the fabricated sensor has a measuring sensitivity of~19 Hz/kPa and a nonlinearity of 0.02%full scale in the pressure range of 0–200 kPa at a full temperature range of−40 to 80°C.The sensor also shows a good quality factor>25,000,which demonstrates the good vacuum performance.Thus,the feasibility of the design is a commendable solution for high-accuracy pressure measurements.
基金supported in part by the National Key Research and Development Program of China(2021YFB3203200)the Natural Science Foundation of Shaanxi(2022JQ-554).
文摘Pressure sensors play a vital role in aerospace,automotive,medical,and consumer electronics.Although microelectromechanical system(MEMS)-based pressure sensors have been widely used for decades,new trends in pressure sensors,including higher sensitivity,higher accuracy,better multifunctionality,smaller chip size,and smaller package size,have recently emerged.The demand for performance upgradation has led to breakthroughs in sensor materials,design,fabrication,and packaging methods,which have emerged frequently in recent decades.This paper reviews common new trends in MEMS pressure sensors,including minute differential pressure sensors(MDPSs),resonant pressure sensors(RPSs),integrated pressure sensors,miniaturized pressure chips,and leadless pressure sensors.To realize an extremely sensitive MDPS with broad application potential,including in medical ventilators and fire residual pressure monitors,the“beam-membrane-island”sensor design exhibits the best performance of 66μV/V/kPa with a natural frequency of 11.3 kHz.In high-accuracy applications,silicon and quartz RPS are analyzed,and both materials show±0.01%FS accuracy with respect to varying temperature coefficient of frequency(TCF)control methods.To improve MEMS sensor integration,different integrated“pressure+x”sensor designs and fabrication methods are compared.In this realm,the intercoupling effect still requires further investigation.Typical fabrication methods for microsized pressure sensor chips are also reviewed.To date,the chip thickness size can be controlled to be<0.1 mm,which is advantageous for implant sensors.Furthermore,a leadless pressure sensor was analyzed,offering an extremely small package size and harsh environmental compatibility.This review is structured as follows.The background of pressure sensors is first presented.Then,an in-depth introduction to MEMS pressure sensors based on different application scenarios is provided.Additionally,their respective characteristics and significant advancements are analyzed and summarized.Finally,development trends of MEMS pressure sensors in different fields are analyzed.
基金supported by the National Basic Research Program of China(2013CB933701)the National Natural Science Foundation of China(21127901+2 种基金9141311991213305)the Chinese Academy of Science
文摘Single-particle tracking photoactivated local- ization microscopy （sptPALM） has recently emerged as a powerful tool for high-density imaging and tracking of individual molecules in living cells. In this work, we have monitored and compared the diffusion dynamics of TGF-β type II receptor （TβRII） at high expression level using both traditional single-particle tracking （SPT） and sptPALM. The ligand-induced aggregation of TβRII oligomers was further indicated by sptPALM. Due to the capacity of distinguishing and tracking single molecules within diffraction limit, sptPALM outperforms traditional SPT by providing more accurate biophysical information,
基金supported by grants from the Hong Kong Research Grants Council(Ref.nos.Cl 134-20G and 11211421)the Shenzhen Science and Technology Project,China(Ref no SGDX2020110309300502)+1 种基金the National Science Foundation of China(Ref.no 52105589)the RGC Postdoctoral Fellowship Scheme(PDFS)(Ref.no PDFS2021-1S05).
文摘Highly precise micromanipulation tools that can manipulate and interrogate cell organelles and components must be developed to support the rapid development of new cell-based medical therapies,thereby facilitating in-depth understanding of cell dynamics,cell component functions,and disease mechanisms.This paper presents a literature review on micro/nanomanipulation tools and their control methods for single-cell surgery.Micromanipulation methods specifically based on laser,microneedle,and untethered micro/nanotools are presented in detail.The limitations of these techniques are also discussed.The biological significance and clinical applications of single-cell surgery are also addressed in this paper.
文摘Abstract A novel micro-electromechanical systems piezoresistive pressure sensor with a diagonally positioned peninsula-island structure has high sensitivity for ultra- low-pressure measurement. The pressure sensor was designed with a working range of 0-500 Pa and had a high sensitivity of 0.06 mV-V^-1-Pa-1. The trade-off between high sensitivity and linearity was alleviated. Moreover, the influence of the installation angle on the sensing chip output was analyzed, and an application experiment of the sensor was conducted using the built pipettor test platform. Findings indicated that the proposed pressure sensor had sufficient resolution ability and accuracy to detect the pressure variation in the pipettor chamber. Therefore, the proposed pressure sensor has strong potential for medical equipment application.
基金the National Natural Science Foundation of China(No.52175517,51720105016)Zhejiang Lab(No.2022MG0AB03)+3 种基金China Postdoctoral Science Foundation(No.2017M610634)Shaanxi Postdoctoral Science Foundation(No.2017BSHEDZZ73)National Key Research&Development(R&D)Program of China(Grant No.2016YFB0501600)the Recruitment Program of Global Experts(Grant No.WQ2017610445)for their support.
文摘Flexible strain sensors are promising candidates for intelligent wearable devices.Among previous studies,although crack-based sensors have attracted a lot of attention due to their ultrahigh sensitivity,large strain usually causes fractures in the conductive paths.Because of the unstable crack structure,the tradeoff between sensitivity and workable strain range is still a challenge.As carbon nanotubes(CNTs)and silver nanowires(AgNWs)can form a strong interface with the thermoplastic substrate and strengthen the conductive network by capillary force during water evaporation,CNTs and AgNWs were deposited on electrospun TPU fiber mats via vacuum-assisted filtration in this work.The prestretching treatment constructed a microcrack structure that endowed the sensor with the combined characteristics of a wide working range(0~171%strain),ultrahigh sensitivity(a gauge factor of 691 within 0~102%strain,~2×10^(4) within 102~135%strain,and>11×10^(4) within 135~171%strain),a fast response time(~65 ms),small hysteresis,and superior durability(>2000 cycles).Subsequently,the sensing mechanism of the sensor was studied.Distributed microcrack propagation based on the“island-bridge”structure was explained in detail,and its influence on the strain-sensing behavior of the sensor was analyzed.Finally,the sensor was assembled to monitor various vibration signals and human motions,demonstrating its potential applications in the fields of electronic skin and human health monitoring.
