In conventional nondispersive infrared(NDIR)gas sensors,a wide-spectrum IR source or detector must be combined with a narrowband filter to eliminate the interference of nontarget gases.Therefore,the multiplexed NDIR g...In conventional nondispersive infrared(NDIR)gas sensors,a wide-spectrum IR source or detector must be combined with a narrowband filter to eliminate the interference of nontarget gases.Therefore,the multiplexed NDIR gas sensor requires multiple pairs of narrowband filters,which is not conducive to miniaturization and integration.Although plasmonic metamaterials or multilayer thin-film structures are widely applied in spectral absorption filters,realizing high-performance,large-area,multiband,and compact filters is rather challenging.In this study,we propose and demonstrate a narrowband meta-absorber based on a planar metal–insulator–metal(MIM)cavity with a metallic ultrathin film atop.Nearly perfect absorption of different wavelengths can be obtained by controlling the thickness of the dielectric spacer.More significantly,the proposed meta-absorber exhibits angle-dependent characteristics.The absorption spectra of different gases can be matched by changing the incident angle of the light source.We also preliminarily investigate the CO_(2) gas sensing capability of the meta-absorber.Afterward,we propose a tunable meta-absorber integrated with a microelectromechanical system(MEMS)-based electrothermal actuator(ETA).By applying a direct current(DC)bias voltage,the inclination angle of the meta-absorber can be controlled,and the relationship between the inclination angle and the applied voltage can be deduced theoretically.The concept of a tunable MEMS-based meta-absorber offers a new way toward highly integrated,miniaturized and energy-efficient NDIR multigas sensing systems.展开更多
The alarming prevalence and mortality rates associated with cardiovascular diseases have emphasized the urgency for innovative detection solutions.Traditional methods,often costly,bulky,and prone to subjectivity,fall ...The alarming prevalence and mortality rates associated with cardiovascular diseases have emphasized the urgency for innovative detection solutions.Traditional methods,often costly,bulky,and prone to subjectivity,fall short of meeting the need for daily monitoring.Digital and portable wearable monitoring devices have emerged as a promising research frontier.This study introduces a wearable system that integrates electrocardiogram(ECG)and phonocardiogram(PCG)detection.By ingeniously pairing a contact-type PZT heart sound sensing structure with ECG electrodes,the system achieves the acquisition of high-quality ECG and PCG signals.Notably,the signal-to-noise ratios(SNR)for ECG and PCG signals were measured at 44.13 dB and 30.04 dB,respectively,demonstrating the system’s remarkable stability across varying conditions.These collected signals were subsequently utilized to derive crucial feature values,including electromechanical delay(EMD),left ventricular ejection time(LVET),and pre-ejection period(PEP).Furthermore,we collected a dataset comprising 40 cases of ECG and PCG signals,enabling a comparative analysis of these three feature parameters between healthy individuals and coronary heart disease patients.This research endeavor presents a significant step forward in the realm of early,non-invasive,and intelligent monitoring of cardiovascular diseases,offering hope for earlier detection and more effective management of these life-threatening conditions.展开更多
Flexible devices are increasingly crucial in various aspects of our lives,including healthcare devices and humanmachine interface systems,revolutionizing human life.As technology evolves rapidly,there is a high demand...Flexible devices are increasingly crucial in various aspects of our lives,including healthcare devices and humanmachine interface systems,revolutionizing human life.As technology evolves rapidly,there is a high demand for innovative manufacturing methods that enable rapid prototyping of custom and multifunctional flexible devices with high quality.Recently,digital light processing(DLP)3D printing has emerged as a promising manufacturing approach due to its capabilities of creating intricate customized structures,high fabrication speed,low-cost technology and widespread adoption.This review provides a state-of-the-art overview of the recent advances in the creation of flexible devices using DLP printing,with a focus on soft actuators,flexible sensors and flexible energy devices.We emphasize how DLP printing and the development of DLP printable materials enhance the structural design,sensitivity,mechanical performance,and overall functionality of these devices.Finally,we discuss the challenges and perspectives associated with DLP-printed flexible devices.We anticipate that the continued advancements in DLP printing will foster the development of smarter flexible devices,shortening the design-to-manufacturing cycles.展开更多
A tip-tilt-piston 3×3 electrothermal micromirror array(MMA)integrated with temperature field-based position sensors is designed and fabricated in this work.The size of the individual octagonal mirror plates is as...A tip-tilt-piston 3×3 electrothermal micromirror array(MMA)integrated with temperature field-based position sensors is designed and fabricated in this work.The size of the individual octagonal mirror plates is as large as 1.6 mm×1.6 mm.Thermal isolation structures are embedded to reduce the thermal coupling among the micromirror units.Results show that each micromirror unit has a piston scan range of 218μm and a tip-tilt optical scan angle of 21°at only 5 Vdc.The micromirrors also exhibit good dynamic performance with a rise time of 51.2 ms and a fall time of 53.6 ms.Moreover,the on-chip position sensors are proven to be capable for covering the full-range movement of the mirror plate,with the measured sensitivities of 1.5 mV/μm and 8.8 mV/°in piston sensing and tip-tilt sensing,respectively.Furthermore,the thermal crosstalk in an operating MMA has been experimentally studied.The measured results are promising thanks to the embedded thermal isolation structures.展开更多
The quantification of immune cell subpopulations in blood is important for the diagnosis,prognosis and management of various diseases and medical conditions.Flow cytometry is currently the gold standard technique for ...The quantification of immune cell subpopulations in blood is important for the diagnosis,prognosis and management of various diseases and medical conditions.Flow cytometry is currently the gold standard technique for cell quantification;however,it is laborious,time-consuming and relies on bulky/expensive instrumentation,limiting its use to laboratories in high-resource settings.Microfluidic cytometers offering enhanced portability have been developed that are capable of rapid cell quantification;however,these platforms involve tedious sample preparation and processing protocols and/or require the use of specialized/expensive instrumentation for flow control and cell detection.Here,we report an artificial intelligence-enabled microfluidic cytometer for rapid CD4^(+)T cell quantification in whole blood requiring minimal sample preparation and instrumentation.CD4^(+)T cells in blood are labeled with anti-CD4 antibody-coated microbeads,which are driven through a microfluidic chip via gravity-driven slug flow,enabling pump-free operation.A video of the sample flowing in the chip is recorded using a microscope camera,which is analyzed using a convolutional neural network-based model that is trained to detect bead-labeled cells in the blood flow.The functionality of this platform was evaluated by analyzing fingerprick blood samples obtained from healthy donors,which revealed its ability to quantify CD4^(+)T cells with similar accuracy as flow cytometry(<10%deviation between both methods)while being at least 4×faster,less expensive,and simpler to operate.We envision that this platform can be readily modified to quantify other cell subpopulations in blood by using beads coated with different antibodies,making it a promising tool for performing cell count measurements outside of laboratories and in low-resource settings.展开更多
Large-area gratings play a crucial role in various engineering fields.However,traditional interference lithography is limited by the size of optical component apertures,making large-area fabrication a challenging task...Large-area gratings play a crucial role in various engineering fields.However,traditional interference lithography is limited by the size of optical component apertures,making large-area fabrication a challenging task.Here,a method for fabricating laser interference lithography pattern arrays with a global alignment reference strategy is proposed.This approach enables alignment of each area of the laser interference lithography pattern arrays,including phase,period,and tilt angle.Two reference gratings are utilized:one is detached from the substrate,while the other remains fixed to it.To achieve global alignment,the exposure area is adjusted by alternating between moving the beam and the substrate.In our experiment,a 3×3 regions grating array was fabricated,and the−1st-order diffraction wavefront measured by the Fizeau interferometer exhibited good continuity.This technique enables effective and efficient alignment with high accuracy across any region in an interference lithography pattern array on large substrates.It can also serve as a common technique for fabricating various types of periodic structures by rotating the substrate.展开更多
This study presents a wafer-level sealed silicon cavity(SSC)microacoustic integration platform to address the limitations in the cavity Silicon-on-Insulator(C-SOI)wafers for the 5G/6G wireless communication system.The...This study presents a wafer-level sealed silicon cavity(SSC)microacoustic integration platform to address the limitations in the cavity Silicon-on-Insulator(C-SOI)wafers for the 5G/6G wireless communication system.The proposed SSC platform features an extremely smooth suspended membrane with adjustable thickness,flexible cavity shapes with high density,self-formed acoustic wave confinement steps,stable temperature coefficient of frequency(TCF),and highly integrated compatibility with complementary metal-oxide semiconductor(CMOS).A surface smoothing method based on wet oxidation for SSC wafers is presented,which achieves a root mean square(RMS)roughness on the cavity surface of 1.5 nm for the first time.Based on the presented SSC platform,an Al_(0.75)Sc_(0.25)N sealed cavity bulk acoustic wave resonator(S-BAR)is designed,fabricated,and characterized.The experimental results show that the asymmetric second-order(A2)Lamb mode of S-BAR is enhanced for higher frequency with a maximum piezoelectric coupling coefficient(k_(t)^(2))of 9.53%,a maximum quality factor(Q)of 439,and a TCF of−11.44 ppm/K.Different designs’piezoelectric coupling coefficient distribution is consistent with the theoretical prediction.The proposed smoothing process increases the S-BARs’quality factor by~400%.The frequency shift caused by the temperature(absolute value of TCF)is reduced by 62%compared with the traditional Al_(0.75)Sc_(0.25)N thin film bulk acoustic wave resonator(without temperature compensation).The enhanced performances demonstrated the potential of SSC in the next-generation highly integrated RF communication systems.展开更多
In this work,we introduce a novel Micro Circular Log-Periodic Antenna(MCLPA)optimized with an advanced Evolutionary Neural Network(ENN)algorithm,specifically designed to enhance terahertz(THz)radiation detection.By le...In this work,we introduce a novel Micro Circular Log-Periodic Antenna(MCLPA)optimized with an advanced Evolutionary Neural Network(ENN)algorithm,specifically designed to enhance terahertz(THz)radiation detection.By leveraging the adaptive capabilities of the ENN framework,the antenna design efficiency is significantly improved,enabling rapid prototyping and yielding highly optimized structures tailored for practical THz applications.Extensive characterization confirms that the proposed MCLPA achieves outstanding performance,including an ultra-broad operational bandwidth of 372 GHz(0.135-0.507 THz),a peak gain of 5.51 dBi,an optimal S-parameter(S11)of−13.68 dB,and a maximum radiation efficiency of 82.39%.In addition,the MCLPA exhibits superior sensitivity,low noise susceptibility,and fast response,which are key attributes for reliable and precise THz detection.When configured in array form,the design further enhances gain and directional responsiveness,demonstrating the scalability and deployment potential of the MCLPA.This ENN-driven MCLPA represents a significant breakthrough in THz antenna engineering,introducing a transformative design paradigm that synergistically integrates algorithmic intelligence with structural innovation.By substantially reducing design time and cost while achieving exceptional performance,the proposed ENN framework sets a new benchmark for the development of next-generation THz detection and communication systems,offering broad implications for future high-frequency technologies.展开更多
Early equipment fault diagnosis can identify potential risks,significantly reduce maintenance costs,and minimize property damage.However,vibration,strain,and force sensors operating at low frequencies with narrow band...Early equipment fault diagnosis can identify potential risks,significantly reduce maintenance costs,and minimize property damage.However,vibration,strain,and force sensors operating at low frequencies with narrow bandwidths are insufficiently sensitive to fault information,making early fault prediction challenging.Here,we introduce a high-performance,cost-effective,and tiny-sized micro-electromechanical system(MEMS)acoustic emission sensor.This sensor utilizes a 10×11 hexagonal array of piezoelectric micromachined ultrasonic transducers with a chip size of 4 mm×4 mm×0.4 mm.The sensor is encapsulated using an epoxy/Al_(2)O_(3) composite for acoustic impedance matching,and its overall size isΦ16 mm×H 5.5 mm,with a weight of approximately 3 g.This acoustic emission sensor achieves a peak sensitivity of 88.4 dB(ref.V/(m/s))at 335 kHz,and its sensitivity remains above 60 dB across the frequency range from 15 kHz to 620 kHz.In addition,combined with the residual neural networks,an intelligent fault diagnosis of the planetary gear is realized.This MEMS acoustic emission sensor can provide a promising approach for in-situ fault monitoring of highly integrated and miniaturized industrial equipment.展开更多
Lateral flow assays(LFAs)are widely used in point-of-care testing(POCT)due to their simplicity and rapid operation.However,their reliance on passive capillary flow limits sensitivity,making it challenging to detect lo...Lateral flow assays(LFAs)are widely used in point-of-care testing(POCT)due to their simplicity and rapid operation.However,their reliance on passive capillary flow limits sensitivity,making it challenging to detect low-abundance biomarkers accurately.Approaches such as computer signal processing,chemical modification,and physical regulation have been explored to improve LFA sensitivity,but they remain limited by passive capillary-driven flow and uncontrollable flow rate.An alternative approach is to actively regulate fluid dynamics to optimize analyte binding and signal generation.The key challenge is to enhance LFA sensitivity while preserving compatibility with existing lateral flow strips(LFSs).Here,this study introduces a centrifugation-assisted LFA(CLFA)platform with smartphone-based result processing.This platform applies centrifugal force opposite to capillary flow,actively regulating fluid movement to optimize incubation time at the reaction zone and enhance detection performance.This approach increases signal intensity while maintaining a rapid detection process(5 min)and ensuring integration with traditional LFSs.As a proof-of-concept,the CLFA platform successfully detected human chorionic gonadotropin(hCG)and hemoglobin(Hb)in artificial urine without requiring custom-designed centrifugal discs or modified chromatography membranes.Its adaptability to diverse biomarkers and smartphone-based quantification make it a promising POCT tool,particularly in resource-limited settings.展开更多
Flexible tactile sensors are receiving considerable interest due to their potential in diverse fields,including physiological monitoring and wearable electronics.Despite numerous studies to broaden their practical use...Flexible tactile sensors are receiving considerable interest due to their potential in diverse fields,including physiological monitoring and wearable electronics.Despite numerous studies to broaden their practical use,it remains difficult to simultaneously attain high sensitivity and a wide-range pressure detection.In this study,we have fabricated a tactile sensor with highly porous three-dimensional conductive architecture based on carbon nanotubes(CNTs)functionalized with gold nanoparticles(AuNPs).The zero-dimensional AuNPs,directly precipitated onto the CNT surface,exerted minimal effect on the sensor’s initial resistance.Upon applying pressure to the tactile sensor,the contact resistance among the AuNPs-precipitated CNTs changes significantly,resulting in a high sensitivity of 23.23 kPa^(-1) in the low-pressure range(0.05-500 kPa)and 11.06 kPa^(-1) in the high-pressure range(500-1125 kPa).The sensor also exhibits outstanding sensing characteristics,including low hysteresis and excellent repeatability.Leveraging these advantages,the sensor has successfully detected pulse wave signals,neck/jaw muscle movements,and walking motions,confirming its practical applicability in wearable healthcare technologies.展开更多
Raman spectroscopy offers non-destructive and highly sensitive molecular insights into bacterial species,making it a valuable tool for detection,identification,and antibiotic susceptibility testing.However,achieving c...Raman spectroscopy offers non-destructive and highly sensitive molecular insights into bacterial species,making it a valuable tool for detection,identification,and antibiotic susceptibility testing.However,achieving clinically relevant accuracy,quantitative data,and reproducibility remains challenging due to the dominance of bulk signals and the uncontrollable heterogeneity of analytes.In this study,we introduce an innovative diagnostic tool:a plasmonic fidget spinner(P-FS)incorporating a nitrocellulose membrane integrated with a metallic feature,referred to as a nanoplasmonic-enhanced matrix,designed for simultaneous bacterial filtration and detection.We developed a method to fabricate a plasmonic array patterned nitrocellulose membrane using photolithography,which is then integrated with a customized fidget spinner.Testing the P-FS device with various bacterial species(E.coli 25922,S.aureus 25923,E.coli MG1655,Lactobacillus brevis,and S.mutans 3065)demonstrated successful identification based on their unique Raman fingerprints.The bacterial interface with regions within the plasmonic array,where the electromagnetic field is most intensely concentrated—called nanoplasmonic hotspots—on the P-FS significantly enhances sensitivity,enabling more precise detection.SERS intensity mappings from the Raman spectrometer are transformed into digital signals using a threshold-based approach to identify and quantify bacterial distribution.Given the P-FS’s ability to enhance vibrational signatures and its scalable fabrication under routine conditions,we anticipate that nanoplasmonic-enhanced Raman spectroscopy—utilizing nanostructures made from metals(specifically gold and silver)deposited onto a nitrocellulose membrane to amplify Raman scattering signals—will become the preferred technology for reliable and ultrasensitive detection of various analytes,including those crucial to human health,with strong potential for transitioning from laboratory research to clinical applications.展开更多
The demand for highly sensitive and accurate sensors has grown significantly,particularly in the field of Micro-Electro-Mechanical Systems technology.Mode-localized sensors based on weakly coupled resonators have garn...The demand for highly sensitive and accurate sensors has grown significantly,particularly in the field of Micro-Electro-Mechanical Systems technology.Mode-localized sensors based on weakly coupled resonators have garnered attention for their high sensitivity through amplitude ratio outputs.However,when measuring multiple signals by weakly coupled resonators,different signals can interfere with each other,causing high cross-sensitivity.This cross-sensitivity greatly complicates signal separation and makes accurate measurement extremely difficult,impacting system performance.To address this issue,the study proposes an innovative constant-drive technique of weakly coupled resonators.This technique significantly reduces crosstalk between signals while maintaining high sensitivity of amplitude ratio output.The method is theoretically validated by analyzing amplitude ratios under signal perturbations in non-damped conditions,demonstrating perfect elimination of cross-interference.Finite element analysis under damping conditions further validated the constant-drive technique,showing a cross-sensitivity of 0.054%,nearly three orders of magnitude lower than that of mode-localized sensors.Experimental validation confirmed the effectiveness of the proposed technique,with the cross-sensitivity of the mode-localized method measured at 26.3%and 28.7%,respectively,while the constant-frequency drive achieved significantly lower values of 3.1%and 1.1%.This demonstrates a successful reduction in cross-sensitivity by an order of magnitude,meeting the performance requirements for typical MEMS biaxial sensor applications.This method is highly significant for mode-localized sensors,offering potential for developing multi-signal measurement devices like multi-axis accelerometers,force sensor,electric field sensor and mass sensor.展开更多
Precise and long-term electroanalysis at the single-cell level is crucial for the accurate diagnosis and monitoring of brain diseases.The reliable protection in areas outside the signal acquisition points at sharp ult...Precise and long-term electroanalysis at the single-cell level is crucial for the accurate diagnosis and monitoring of brain diseases.The reliable protection in areas outside the signal acquisition points at sharp ultramicroelectrode(UME)tips has a significant impact on the sensitivity,fidelity,and stability of intracellular neural signal recording.However,it is difficult for existing UMEs to achieve controllable exposure of the tip functional structure,which affects their ability to resist environmental interference and shield noise,resulting in unsatisfactory signal-to-noise ratio and signal fidelity of intracellular recordings.To address this issue,we chose a dense and electrochemically stable diamond-like carbon(DLC)film as the UME protection coating and developed a method to precisely control the exposed degree of the functional structure by directly fixed-point processing of the UME tip by the strong site-selectivity and good controllability of the atmospheric microplasma jet.By analyzing the interaction between the microplasma jet and the UME tip,as well as the changes in the removal length and microstructure of UME tips with processing time,the exposed tip length was precisely controlled down to the submicron scale.Biocompatibility experiments,electrochemical aging tests and real-time intracellular pH recording experiments have demonstrated that the DLC-UME with effective tip protection processed by microplasma jet has the potential to enable long-term detection of intracellular high-fidelity signals.展开更多
This study presents an innovative urea detection method utilizing pH-controlled Fenton etching of gold nanobipyramids(AuNBPs),offering a multicolor visual response.By leveraging the urease-catalyzed hydrolysis of urea...This study presents an innovative urea detection method utilizing pH-controlled Fenton etching of gold nanobipyramids(AuNBPs),offering a multicolor visual response.By leveraging the urease-catalyzed hydrolysis of urea,which releases ammonia and raises pH,the Fenton reaction is inhibited,reducing the etching of AuNBPs.This approach enables a highly sensitive and distinct multichromatic response across a wide range of urea concentrations,particularly at low target levels.The solution-based sensor achieved an exceptionally low detection limit of 0.098μM,surpassing existing colorimetric urea biosensors.Furthermore,embedding the sensor in an agarose hydrogel matrix to create a solid-state format resulted in a detection limit of 0.2μM.Real-world validation demonstrated high recovery rates in urine samples,further affirming the sensor’s reliability.This multicolor biosensing platform offers a robust tool for point-of-care diagnostics,facilitating accurate and user-friendly urea detection.展开更多
As transparent electrodes,patterned silver nanowire(AgNW)networks suffer from noticeable pattern visibility,which is an unsettled issue for practical applications such as display.Here,we introduce a Gibbs-Thomson effe...As transparent electrodes,patterned silver nanowire(AgNW)networks suffer from noticeable pattern visibility,which is an unsettled issue for practical applications such as display.Here,we introduce a Gibbs-Thomson effect(GTE)-based patterning method to effectively reduce pattern visibility.Unlike conventional top-down and bottom-up strategies that rely on selective etching,removal,or deposition of AgNWs,our approach focuses on fragmenting nanowires primarily at the junctions through the GTE.This is realized by modifying AgNWs with a compound of diphenyliodonium nitrate and silver nitrate,which aggregates into nanoparticles at the junctions of AgNWs.These nanoparticles can boost the fragmentation of nanowires at the junctions under an ultralow temperature(75℃),allow pattern transfer through a photolithographic masking operation,and enhance plasmonic welding during UV exposure.The resultant patterned electrodes have trivial differences in transmittance(ΔT=1.4%)and haze(ΔH=0.3%)between conductive and insulative regions,with high-resolution patterning size down to 10μm.To demonstrate the practicality of this novel method,we constructed a highly transparent,optoelectrical interactive tactile e-skin using the patterned AgNW electrodes.展开更多
Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and ...Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and is easy to use.However,the driving forces created by hydraulic head differences gradually decrease during operation,resulting in decreasing flow rates that are undesirable in many microfluidic applications such as perfusion culture,droplet microfluidics,etc.Existing methods to maintain a constant gravity-driven flow either require additional control equipment,involve complex fabrication or operation,are incompatible with miniaturization,or introduce interfaces that lack robustness.Here we tackled those problems by introducing a 3D-printed compact hydraulic head auto-regulating module that automatically maintains a constant fluid level at the microfluidic inlet port without human intervention.Our module successfully maintained a constant hydraulic head for more than 24 h,with the operation time solely limited by the reservoir capacity.A comparison with the conventional gravity-driven flow demonstrated our device’s capability to produce a more stable flow over the perfusion period.Overall,our module creates a simple,robust solution to produce a stable flow rate in gravity-driven flow systems.The compactness of the design allows easy parallelization and compatibility with high-throughput applications,and the biocompatibility of the materials enables the device’s use with life science applications.展开更多
The rapid miniaturization of electronic devices has fueled unprecedented demand for flexible,high-performance sensors across fields ranging from medical devices to robotics.Despite advances in fabrication techniques,t...The rapid miniaturization of electronic devices has fueled unprecedented demand for flexible,high-performance sensors across fields ranging from medical devices to robotics.Despite advances in fabrication techniques,the development of micro-and nano-scale flexible force sensors with superior sensitivity,stability,and biocompatibility remains a formidable challenge.In this study,we developed a novel conductive photosensitive resin specifically designed for two-photon polymerization,systematically optimized its printing parameters,and improved its structural design,thereby enabling the fabrication of high-precision micro-spring force sensors(MSFS).The proposed photosensitive resin,doped with MXene nanomaterials,combines exceptional mechanical strength and conductivity,overcoming limitations of traditional materials.Using a support vector machine model in machine learning techniques,we optimized the polymerizability of the resin under varied laser parameters,achieving a predictive accuracy of 92.66%.This model significantly reduced trial-and-error in the TPP process,accelerating the discovery of ideal fabrication conditions.Finite element analysis was employed to design and simulate the performance of the MSFS,guiding structural optimization to achieve high sensitivity and mechanical stability.The fabricated MSFS demonstrated outstanding electromechanical performance,with a sensitivity coefficient of 5.65 and a fabrication accuracy within±50 nm,setting a new standard for MSFS precision.This work not only pushes the boundaries of sensor miniaturization but also introduces a scalable,efficient pathway for the rapid design and fabrication of highperformance flexible sensors.展开更多
With the rapid development of intelligent and autonomous systems,such as wearable health monitoring and advanced manufacturing robots,there is a growing demand for the development of advanced,miniaturized smart sensor...With the rapid development of intelligent and autonomous systems,such as wearable health monitoring and advanced manufacturing robots,there is a growing demand for the development of advanced,miniaturized smart sensors and actuator systems.In this context,a single microdevice with hybrid functionality as both a sensor and actuator demonstrates excellent performance across diverse applications,holds significant promise.Herein,we present a proof-of-concept for a high-performance bi-directional Lorentz force magnetometer and actuator,implemented within a single microelectromechanical system(MEMS)device.Moreover,the device demonstrates insensitivity to magnetic fields,making it highly suitable for applications that require anti-crossing behavior in magnetic environments.The design is based on a clamped-guided curved microresonator connected to straight and V-shaped beams of micro-actuators.The operation of the proposed device relies on the flexibility to control the applied electrothermal excitation in different ways,offering smart thermal actuation and dynamic sensing mechanisms.Furthermore,the proposed technique allows tuning of the first symmetric mode,achieving either a high or low frequency shift based on input power levels.Hence,this study provides valuable insights for improving tunability in sensitivity and power for various actuation mechanisms.At atmospheric pressure and an input power of 19.5 mW,the device functions as a high-performance biaxial magnetic sensor with a sensitivity(S)of~36.58%T^(-1),an excellent linearity in the medium-to-high magnetic field range of±400 mT,and a minimum detectable field,Bmin of 0.83μT Hz^(-1).In contrast,it can be tuned as a magnetic-field-insensitive actuator(S=3.28%T^(-1))with a transversal displacement of~4μm,utilizing a negligible power of 43 mW.The diverse operation highlights its hybrid functionality as an actuator or high-performance sensor.These features,combined with the simplicity of fabrication and low cost,make the proposed microdevice highly promising for developing a three-axis magnetic sensor and actuator network system,as well as for various industrial applications.展开更多
Photothermal conversion-based quantitative polymerase chain reaction(qPCR)is a fast,sensitive,and accurate method to diagnose infectious diseases.However,they have bottlenecks in test throughput scalability,cumbersome...Photothermal conversion-based quantitative polymerase chain reaction(qPCR)is a fast,sensitive,and accurate method to diagnose infectious diseases.However,they have bottlenecks in test throughput scalability,cumbersome oil cover,and a lack of multi-target capability.Here,the authors present an infectious disease diagnostic device with rapid photothermal conversion-based efficient reverse transcription(RT)-qPCR assays on a multi-target chip(idreamqPCR).The authors innovate an off-axis mirror-based three-channel fluorescence intensity measurement method,enabling concurrent non-contact temperature control of 16 mini-well reaction chambers for qPCRs without the necessity of actuating parts.A transparent adhesive film on a graphite mixed polydimethylsiloxane(PDMS)-based PCR chip with mini-wells avoids contamination and bubbles to achieve 16 RT-qPCRs(40 photothermal cycles)within 17 min.Finally,idream-qPCR is validated by amplifying severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)N172 bp,RdRP 100 bp,and E 113 bp genes using Fluorescein amidites(FAM),Carboxytetramethylrhodamine(TAMRA),and Cyanine5(CY5)fluorescent dyes,respectively,with 102.5%efficiency and a limit-of-detection(LoD)equivalent to 0.85 copies/μL.idream-qPCR can be efficiently used to prevent the spread of infectious diseases.展开更多
基金support from Guangdong Science and Technology Program(2024A0505050007)Guangdong Basic and Applied Basic Research Foundation(2024A1515013019).
文摘In conventional nondispersive infrared(NDIR)gas sensors,a wide-spectrum IR source or detector must be combined with a narrowband filter to eliminate the interference of nontarget gases.Therefore,the multiplexed NDIR gas sensor requires multiple pairs of narrowband filters,which is not conducive to miniaturization and integration.Although plasmonic metamaterials or multilayer thin-film structures are widely applied in spectral absorption filters,realizing high-performance,large-area,multiband,and compact filters is rather challenging.In this study,we propose and demonstrate a narrowband meta-absorber based on a planar metal–insulator–metal(MIM)cavity with a metallic ultrathin film atop.Nearly perfect absorption of different wavelengths can be obtained by controlling the thickness of the dielectric spacer.More significantly,the proposed meta-absorber exhibits angle-dependent characteristics.The absorption spectra of different gases can be matched by changing the incident angle of the light source.We also preliminarily investigate the CO_(2) gas sensing capability of the meta-absorber.Afterward,we propose a tunable meta-absorber integrated with a microelectromechanical system(MEMS)-based electrothermal actuator(ETA).By applying a direct current(DC)bias voltage,the inclination angle of the meta-absorber can be controlled,and the relationship between the inclination angle and the applied voltage can be deduced theoretically.The concept of a tunable MEMS-based meta-absorber offers a new way toward highly integrated,miniaturized and energy-efficient NDIR multigas sensing systems.
基金support provided by the Shanxi Province Outstanding Young Academic Leader Program of Colleges and Universities(2024Q043)Basic Research General Program of Shanxi Province(202303021221186)+2 种基金Shanxi College of Technology Scientific Research Startup Fund Project(009018)National Natural Science Foundation of China(62001430)19th Graduate Science and Technology Project of North University of China(20231938).
文摘The alarming prevalence and mortality rates associated with cardiovascular diseases have emphasized the urgency for innovative detection solutions.Traditional methods,often costly,bulky,and prone to subjectivity,fall short of meeting the need for daily monitoring.Digital and portable wearable monitoring devices have emerged as a promising research frontier.This study introduces a wearable system that integrates electrocardiogram(ECG)and phonocardiogram(PCG)detection.By ingeniously pairing a contact-type PZT heart sound sensing structure with ECG electrodes,the system achieves the acquisition of high-quality ECG and PCG signals.Notably,the signal-to-noise ratios(SNR)for ECG and PCG signals were measured at 44.13 dB and 30.04 dB,respectively,demonstrating the system’s remarkable stability across varying conditions.These collected signals were subsequently utilized to derive crucial feature values,including electromechanical delay(EMD),left ventricular ejection time(LVET),and pre-ejection period(PEP).Furthermore,we collected a dataset comprising 40 cases of ECG and PCG signals,enabling a comparative analysis of these three feature parameters between healthy individuals and coronary heart disease patients.This research endeavor presents a significant step forward in the realm of early,non-invasive,and intelligent monitoring of cardiovascular diseases,offering hope for earlier detection and more effective management of these life-threatening conditions.
基金supported by the Science and Technology Development Fund,Macao SAR(0119/2022/A3 and 0009/2023/ITP1)the Research Grant from the University of Macao and the University of Macao Development Foundation(SRG2022-00038-FST and MYRG-GRG2023-00225-FST-UMDF).
文摘Flexible devices are increasingly crucial in various aspects of our lives,including healthcare devices and humanmachine interface systems,revolutionizing human life.As technology evolves rapidly,there is a high demand for innovative manufacturing methods that enable rapid prototyping of custom and multifunctional flexible devices with high quality.Recently,digital light processing(DLP)3D printing has emerged as a promising manufacturing approach due to its capabilities of creating intricate customized structures,high fabrication speed,low-cost technology and widespread adoption.This review provides a state-of-the-art overview of the recent advances in the creation of flexible devices using DLP printing,with a focus on soft actuators,flexible sensors and flexible energy devices.We emphasize how DLP printing and the development of DLP printable materials enhance the structural design,sensitivity,mechanical performance,and overall functionality of these devices.Finally,we discuss the challenges and perspectives associated with DLP-printed flexible devices.We anticipate that the continued advancements in DLP printing will foster the development of smarter flexible devices,shortening the design-to-manufacturing cycles.
基金funded in part by National Natural Science Foundation of China under Grants 62350710218,92373105 and 62074015National Key Research and Development Program of China(2023YFB3507300).
文摘A tip-tilt-piston 3×3 electrothermal micromirror array(MMA)integrated with temperature field-based position sensors is designed and fabricated in this work.The size of the individual octagonal mirror plates is as large as 1.6 mm×1.6 mm.Thermal isolation structures are embedded to reduce the thermal coupling among the micromirror units.Results show that each micromirror unit has a piston scan range of 218μm and a tip-tilt optical scan angle of 21°at only 5 Vdc.The micromirrors also exhibit good dynamic performance with a rise time of 51.2 ms and a fall time of 53.6 ms.Moreover,the on-chip position sensors are proven to be capable for covering the full-range movement of the mirror plate,with the measured sensitivities of 1.5 mV/μm and 8.8 mV/°in piston sensing and tip-tilt sensing,respectively.Furthermore,the thermal crosstalk in an operating MMA has been experimentally studied.The measured results are promising thanks to the embedded thermal isolation structures.
基金supported in part by the National Institutes of Health(R21CA283852)a Rice University COVID-19 Research Award(U50807).
文摘The quantification of immune cell subpopulations in blood is important for the diagnosis,prognosis and management of various diseases and medical conditions.Flow cytometry is currently the gold standard technique for cell quantification;however,it is laborious,time-consuming and relies on bulky/expensive instrumentation,limiting its use to laboratories in high-resource settings.Microfluidic cytometers offering enhanced portability have been developed that are capable of rapid cell quantification;however,these platforms involve tedious sample preparation and processing protocols and/or require the use of specialized/expensive instrumentation for flow control and cell detection.Here,we report an artificial intelligence-enabled microfluidic cytometer for rapid CD4^(+)T cell quantification in whole blood requiring minimal sample preparation and instrumentation.CD4^(+)T cells in blood are labeled with anti-CD4 antibody-coated microbeads,which are driven through a microfluidic chip via gravity-driven slug flow,enabling pump-free operation.A video of the sample flowing in the chip is recorded using a microscope camera,which is analyzed using a convolutional neural network-based model that is trained to detect bead-labeled cells in the blood flow.The functionality of this platform was evaluated by analyzing fingerprick blood samples obtained from healthy donors,which revealed its ability to quantify CD4^(+)T cells with similar accuracy as flow cytometry(<10%deviation between both methods)while being at least 4×faster,less expensive,and simpler to operate.We envision that this platform can be readily modified to quantify other cell subpopulations in blood by using beads coated with different antibodies,making it a promising tool for performing cell count measurements outside of laboratories and in low-resource settings.
基金supported by the National Natural Science Foundation of China(no.62275142)the Shenzhen Stable Supporting Program(no.WDZC20231124201906001).
文摘Large-area gratings play a crucial role in various engineering fields.However,traditional interference lithography is limited by the size of optical component apertures,making large-area fabrication a challenging task.Here,a method for fabricating laser interference lithography pattern arrays with a global alignment reference strategy is proposed.This approach enables alignment of each area of the laser interference lithography pattern arrays,including phase,period,and tilt angle.Two reference gratings are utilized:one is detached from the substrate,while the other remains fixed to it.To achieve global alignment,the exposure area is adjusted by alternating between moving the beam and the substrate.In our experiment,a 3×3 regions grating array was fabricated,and the−1st-order diffraction wavefront measured by the Fizeau interferometer exhibited good continuity.This technique enables effective and efficient alignment with high accuracy across any region in an interference lithography pattern array on large substrates.It can also serve as a common technique for fabricating various types of periodic structures by rotating the substrate.
基金supported in part by the Hong Kong Research Grants Council 26202122in part by the National Natural Science Foundation of China 62304193+1 种基金in part by the Hong Kong Innovation and Technology Commission MHP/007/22in part by the Hong Kong RGC Strategic Topics Grant STG3/E-602/23N.
文摘This study presents a wafer-level sealed silicon cavity(SSC)microacoustic integration platform to address the limitations in the cavity Silicon-on-Insulator(C-SOI)wafers for the 5G/6G wireless communication system.The proposed SSC platform features an extremely smooth suspended membrane with adjustable thickness,flexible cavity shapes with high density,self-formed acoustic wave confinement steps,stable temperature coefficient of frequency(TCF),and highly integrated compatibility with complementary metal-oxide semiconductor(CMOS).A surface smoothing method based on wet oxidation for SSC wafers is presented,which achieves a root mean square(RMS)roughness on the cavity surface of 1.5 nm for the first time.Based on the presented SSC platform,an Al_(0.75)Sc_(0.25)N sealed cavity bulk acoustic wave resonator(S-BAR)is designed,fabricated,and characterized.The experimental results show that the asymmetric second-order(A2)Lamb mode of S-BAR is enhanced for higher frequency with a maximum piezoelectric coupling coefficient(k_(t)^(2))of 9.53%,a maximum quality factor(Q)of 439,and a TCF of−11.44 ppm/K.Different designs’piezoelectric coupling coefficient distribution is consistent with the theoretical prediction.The proposed smoothing process increases the S-BARs’quality factor by~400%.The frequency shift caused by the temperature(absolute value of TCF)is reduced by 62%compared with the traditional Al_(0.75)Sc_(0.25)N thin film bulk acoustic wave resonator(without temperature compensation).The enhanced performances demonstrated the potential of SSC in the next-generation highly integrated RF communication systems.
基金support from the Natural Sciences and Engineering Research Council of Canada(NSERC)and the Micro-Nano Technology(MNT)program facilitated by CMC Microsystems.
文摘In this work,we introduce a novel Micro Circular Log-Periodic Antenna(MCLPA)optimized with an advanced Evolutionary Neural Network(ENN)algorithm,specifically designed to enhance terahertz(THz)radiation detection.By leveraging the adaptive capabilities of the ENN framework,the antenna design efficiency is significantly improved,enabling rapid prototyping and yielding highly optimized structures tailored for practical THz applications.Extensive characterization confirms that the proposed MCLPA achieves outstanding performance,including an ultra-broad operational bandwidth of 372 GHz(0.135-0.507 THz),a peak gain of 5.51 dBi,an optimal S-parameter(S11)of−13.68 dB,and a maximum radiation efficiency of 82.39%.In addition,the MCLPA exhibits superior sensitivity,low noise susceptibility,and fast response,which are key attributes for reliable and precise THz detection.When configured in array form,the design further enhances gain and directional responsiveness,demonstrating the scalability and deployment potential of the MCLPA.This ENN-driven MCLPA represents a significant breakthrough in THz antenna engineering,introducing a transformative design paradigm that synergistically integrates algorithmic intelligence with structural innovation.By substantially reducing design time and cost while achieving exceptional performance,the proposed ENN framework sets a new benchmark for the development of next-generation THz detection and communication systems,offering broad implications for future high-frequency technologies.
基金supported in part by the National Key Research and Development Program of China(Grant No.2022YFB3205400)in part by the Fundamental Research Funds for the Central Universities(Grant No.2024CDJGF-005)in part by the Science Fund for Distinguished Young Scholars of Chongqing(Grant No.CSTB2022 NSCQJQX0006).
文摘Early equipment fault diagnosis can identify potential risks,significantly reduce maintenance costs,and minimize property damage.However,vibration,strain,and force sensors operating at low frequencies with narrow bandwidths are insufficiently sensitive to fault information,making early fault prediction challenging.Here,we introduce a high-performance,cost-effective,and tiny-sized micro-electromechanical system(MEMS)acoustic emission sensor.This sensor utilizes a 10×11 hexagonal array of piezoelectric micromachined ultrasonic transducers with a chip size of 4 mm×4 mm×0.4 mm.The sensor is encapsulated using an epoxy/Al_(2)O_(3) composite for acoustic impedance matching,and its overall size isΦ16 mm×H 5.5 mm,with a weight of approximately 3 g.This acoustic emission sensor achieves a peak sensitivity of 88.4 dB(ref.V/(m/s))at 335 kHz,and its sensitivity remains above 60 dB across the frequency range from 15 kHz to 620 kHz.In addition,combined with the residual neural networks,an intelligent fault diagnosis of the planetary gear is realized.This MEMS acoustic emission sensor can provide a promising approach for in-situ fault monitoring of highly integrated and miniaturized industrial equipment.
基金financial support from the programs of the Natural Science Foundation of the Jiangsu Higher Education(24KJB460030)XJTLU RDF project(RDF-21-02-076)+4 种基金partially supported by the XJTLU AI University Research Centre,Jiangsu Province Engineering Research Centre of Data Science and Cognitive Computation at XJTLUthe SIP AI innovation platform(YZCXPT2022103)Jiangsu Provincial Outstanding Youth Program(BK20230072)Suzhou Industrial Foresight and Key Core Technology Project(SYC2022044)grants from Jiangsu QingLan Project and Jiangsu 333 high-level talents.
文摘Lateral flow assays(LFAs)are widely used in point-of-care testing(POCT)due to their simplicity and rapid operation.However,their reliance on passive capillary flow limits sensitivity,making it challenging to detect low-abundance biomarkers accurately.Approaches such as computer signal processing,chemical modification,and physical regulation have been explored to improve LFA sensitivity,but they remain limited by passive capillary-driven flow and uncontrollable flow rate.An alternative approach is to actively regulate fluid dynamics to optimize analyte binding and signal generation.The key challenge is to enhance LFA sensitivity while preserving compatibility with existing lateral flow strips(LFSs).Here,this study introduces a centrifugation-assisted LFA(CLFA)platform with smartphone-based result processing.This platform applies centrifugal force opposite to capillary flow,actively regulating fluid movement to optimize incubation time at the reaction zone and enhance detection performance.This approach increases signal intensity while maintaining a rapid detection process(5 min)and ensuring integration with traditional LFSs.As a proof-of-concept,the CLFA platform successfully detected human chorionic gonadotropin(hCG)and hemoglobin(Hb)in artificial urine without requiring custom-designed centrifugal discs or modified chromatography membranes.Its adaptability to diverse biomarkers and smartphone-based quantification make it a promising POCT tool,particularly in resource-limited settings.
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(Nos.RS-2024-00457040 and RS-2023-00222166).
文摘Flexible tactile sensors are receiving considerable interest due to their potential in diverse fields,including physiological monitoring and wearable electronics.Despite numerous studies to broaden their practical use,it remains difficult to simultaneously attain high sensitivity and a wide-range pressure detection.In this study,we have fabricated a tactile sensor with highly porous three-dimensional conductive architecture based on carbon nanotubes(CNTs)functionalized with gold nanoparticles(AuNPs).The zero-dimensional AuNPs,directly precipitated onto the CNT surface,exerted minimal effect on the sensor’s initial resistance.Upon applying pressure to the tactile sensor,the contact resistance among the AuNPs-precipitated CNTs changes significantly,resulting in a high sensitivity of 23.23 kPa^(-1) in the low-pressure range(0.05-500 kPa)and 11.06 kPa^(-1) in the high-pressure range(500-1125 kPa).The sensor also exhibits outstanding sensing characteristics,including low hysteresis and excellent repeatability.Leveraging these advantages,the sensor has successfully detected pulse wave signals,neck/jaw muscle movements,and walking motions,confirming its practical applicability in wearable healthcare technologies.
基金supported by the taxpayers of South Korea through the Institute for Basic Science(IBS-R020-D1)the Bio&Medical Technology Development Program of the National Research Foundation(NRF)funded by the Korean government(MSIT)(No.RS-2024-00508821).
文摘Raman spectroscopy offers non-destructive and highly sensitive molecular insights into bacterial species,making it a valuable tool for detection,identification,and antibiotic susceptibility testing.However,achieving clinically relevant accuracy,quantitative data,and reproducibility remains challenging due to the dominance of bulk signals and the uncontrollable heterogeneity of analytes.In this study,we introduce an innovative diagnostic tool:a plasmonic fidget spinner(P-FS)incorporating a nitrocellulose membrane integrated with a metallic feature,referred to as a nanoplasmonic-enhanced matrix,designed for simultaneous bacterial filtration and detection.We developed a method to fabricate a plasmonic array patterned nitrocellulose membrane using photolithography,which is then integrated with a customized fidget spinner.Testing the P-FS device with various bacterial species(E.coli 25922,S.aureus 25923,E.coli MG1655,Lactobacillus brevis,and S.mutans 3065)demonstrated successful identification based on their unique Raman fingerprints.The bacterial interface with regions within the plasmonic array,where the electromagnetic field is most intensely concentrated—called nanoplasmonic hotspots—on the P-FS significantly enhances sensitivity,enabling more precise detection.SERS intensity mappings from the Raman spectrometer are transformed into digital signals using a threshold-based approach to identify and quantify bacterial distribution.Given the P-FS’s ability to enhance vibrational signatures and its scalable fabrication under routine conditions,we anticipate that nanoplasmonic-enhanced Raman spectroscopy—utilizing nanostructures made from metals(specifically gold and silver)deposited onto a nitrocellulose membrane to amplify Raman scattering signals—will become the preferred technology for reliable and ultrasensitive detection of various analytes,including those crucial to human health,with strong potential for transitioning from laboratory research to clinical applications.
基金supported by the National Science Foundation of China(No.52435012 and No.52475606)the National Key Research and Development Program of China(No.2023YFB3208800)+1 种基金Innovation Capability Support Program of Shaanxi(No.2024RS-CXTD-7)the Fundamental Research Funds for the Central Universities.
文摘The demand for highly sensitive and accurate sensors has grown significantly,particularly in the field of Micro-Electro-Mechanical Systems technology.Mode-localized sensors based on weakly coupled resonators have garnered attention for their high sensitivity through amplitude ratio outputs.However,when measuring multiple signals by weakly coupled resonators,different signals can interfere with each other,causing high cross-sensitivity.This cross-sensitivity greatly complicates signal separation and makes accurate measurement extremely difficult,impacting system performance.To address this issue,the study proposes an innovative constant-drive technique of weakly coupled resonators.This technique significantly reduces crosstalk between signals while maintaining high sensitivity of amplitude ratio output.The method is theoretically validated by analyzing amplitude ratios under signal perturbations in non-damped conditions,demonstrating perfect elimination of cross-interference.Finite element analysis under damping conditions further validated the constant-drive technique,showing a cross-sensitivity of 0.054%,nearly three orders of magnitude lower than that of mode-localized sensors.Experimental validation confirmed the effectiveness of the proposed technique,with the cross-sensitivity of the mode-localized method measured at 26.3%and 28.7%,respectively,while the constant-frequency drive achieved significantly lower values of 3.1%and 1.1%.This demonstrates a successful reduction in cross-sensitivity by an order of magnitude,meeting the performance requirements for typical MEMS biaxial sensor applications.This method is highly significant for mode-localized sensors,offering potential for developing multi-signal measurement devices like multi-axis accelerometers,force sensor,electric field sensor and mass sensor.
基金supported by the National Key R&D Program of China under grant 2022YFF120301the Fundamental Research Funds for the Central Universities,the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDA25040100,XDA25040200 and XDA25040300)+4 种基金the National Natural Science Foundation of China(No.42127807-03)Project supported by Shanghai Municipal Science and Technology Major Project(2021SHZDZX)Shanghai Pilot Program for Basic Research-Shanghai Jiao Tong University(No.21TQ1400203)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(No.SL2023ZD205)SJTU Trans-med Award(No.21X010301627).
文摘Precise and long-term electroanalysis at the single-cell level is crucial for the accurate diagnosis and monitoring of brain diseases.The reliable protection in areas outside the signal acquisition points at sharp ultramicroelectrode(UME)tips has a significant impact on the sensitivity,fidelity,and stability of intracellular neural signal recording.However,it is difficult for existing UMEs to achieve controllable exposure of the tip functional structure,which affects their ability to resist environmental interference and shield noise,resulting in unsatisfactory signal-to-noise ratio and signal fidelity of intracellular recordings.To address this issue,we chose a dense and electrochemically stable diamond-like carbon(DLC)film as the UME protection coating and developed a method to precisely control the exposed degree of the functional structure by directly fixed-point processing of the UME tip by the strong site-selectivity and good controllability of the atmospheric microplasma jet.By analyzing the interaction between the microplasma jet and the UME tip,as well as the changes in the removal length and microstructure of UME tips with processing time,the exposed tip length was precisely controlled down to the submicron scale.Biocompatibility experiments,electrochemical aging tests and real-time intracellular pH recording experiments have demonstrated that the DLC-UME with effective tip protection processed by microplasma jet has the potential to enable long-term detection of intracellular high-fidelity signals.
基金supported by the Institute for Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(RS-2023-00228994),RS-2024-00346003the National Research Foundation of Korea(2020R1A5A1018052)and(RS-2024-00410209).
文摘This study presents an innovative urea detection method utilizing pH-controlled Fenton etching of gold nanobipyramids(AuNBPs),offering a multicolor visual response.By leveraging the urease-catalyzed hydrolysis of urea,which releases ammonia and raises pH,the Fenton reaction is inhibited,reducing the etching of AuNBPs.This approach enables a highly sensitive and distinct multichromatic response across a wide range of urea concentrations,particularly at low target levels.The solution-based sensor achieved an exceptionally low detection limit of 0.098μM,surpassing existing colorimetric urea biosensors.Furthermore,embedding the sensor in an agarose hydrogel matrix to create a solid-state format resulted in a detection limit of 0.2μM.Real-world validation demonstrated high recovery rates in urine samples,further affirming the sensor’s reliability.This multicolor biosensing platform offers a robust tool for point-of-care diagnostics,facilitating accurate and user-friendly urea detection.
基金supported by the Basic and Applied Basic Research Foundation of Guangdong Province(2024A1515030155,2022A1515010272,2024A1515012609,2023A1515011459)National Natural Science Foundation of China(61904067,62475101,62175094,62275109)+2 种基金open funding from the State Key Laboratory of Optoelectronic Materials and Technologies(Sun Yat-Sen University,OEMT-2022-KF-08)National Innovation and Entrepreneurship Training Program For Undergraduate(202410559004)Fundamental Research Funds for the Central Universities(11621405).
文摘As transparent electrodes,patterned silver nanowire(AgNW)networks suffer from noticeable pattern visibility,which is an unsettled issue for practical applications such as display.Here,we introduce a Gibbs-Thomson effect(GTE)-based patterning method to effectively reduce pattern visibility.Unlike conventional top-down and bottom-up strategies that rely on selective etching,removal,or deposition of AgNWs,our approach focuses on fragmenting nanowires primarily at the junctions through the GTE.This is realized by modifying AgNWs with a compound of diphenyliodonium nitrate and silver nitrate,which aggregates into nanoparticles at the junctions of AgNWs.These nanoparticles can boost the fragmentation of nanowires at the junctions under an ultralow temperature(75℃),allow pattern transfer through a photolithographic masking operation,and enhance plasmonic welding during UV exposure.The resultant patterned electrodes have trivial differences in transmittance(ΔT=1.4%)and haze(ΔH=0.3%)between conductive and insulative regions,with high-resolution patterning size down to 10μm.To demonstrate the practicality of this novel method,we constructed a highly transparent,optoelectrical interactive tactile e-skin using the patterned AgNW electrodes.
基金supported by the NIH award 1R21NS120088the MIT School of Engineering Postdoctoral Fellowship Program for Engineering Excellence.
文摘Fluid flow is a ubiquitous aspect of microfluidic systems.Gravity-driven flow is one microfluidic flow initiation and maintenance mechanism that is appealing because it is simple,requires no external power source,and is easy to use.However,the driving forces created by hydraulic head differences gradually decrease during operation,resulting in decreasing flow rates that are undesirable in many microfluidic applications such as perfusion culture,droplet microfluidics,etc.Existing methods to maintain a constant gravity-driven flow either require additional control equipment,involve complex fabrication or operation,are incompatible with miniaturization,or introduce interfaces that lack robustness.Here we tackled those problems by introducing a 3D-printed compact hydraulic head auto-regulating module that automatically maintains a constant fluid level at the microfluidic inlet port without human intervention.Our module successfully maintained a constant hydraulic head for more than 24 h,with the operation time solely limited by the reservoir capacity.A comparison with the conventional gravity-driven flow demonstrated our device’s capability to produce a more stable flow over the perfusion period.Overall,our module creates a simple,robust solution to produce a stable flow rate in gravity-driven flow systems.The compactness of the design allows easy parallelization and compatibility with high-throughput applications,and the biocompatibility of the materials enables the device’s use with life science applications.
文摘The rapid miniaturization of electronic devices has fueled unprecedented demand for flexible,high-performance sensors across fields ranging from medical devices to robotics.Despite advances in fabrication techniques,the development of micro-and nano-scale flexible force sensors with superior sensitivity,stability,and biocompatibility remains a formidable challenge.In this study,we developed a novel conductive photosensitive resin specifically designed for two-photon polymerization,systematically optimized its printing parameters,and improved its structural design,thereby enabling the fabrication of high-precision micro-spring force sensors(MSFS).The proposed photosensitive resin,doped with MXene nanomaterials,combines exceptional mechanical strength and conductivity,overcoming limitations of traditional materials.Using a support vector machine model in machine learning techniques,we optimized the polymerizability of the resin under varied laser parameters,achieving a predictive accuracy of 92.66%.This model significantly reduced trial-and-error in the TPP process,accelerating the discovery of ideal fabrication conditions.Finite element analysis was employed to design and simulate the performance of the MSFS,guiding structural optimization to achieve high sensitivity and mechanical stability.The fabricated MSFS demonstrated outstanding electromechanical performance,with a sensitivity coefficient of 5.65 and a fabrication accuracy within±50 nm,setting a new standard for MSFS precision.This work not only pushes the boundaries of sensor miniaturization but also introduces a scalable,efficient pathway for the rapid design and fabrication of highperformance flexible sensors.
基金supported by Khalifa University of Science and Technology(KU)under Award No.FSU-2023-028King Abdullah University of Science and Technology(KAUST).
文摘With the rapid development of intelligent and autonomous systems,such as wearable health monitoring and advanced manufacturing robots,there is a growing demand for the development of advanced,miniaturized smart sensors and actuator systems.In this context,a single microdevice with hybrid functionality as both a sensor and actuator demonstrates excellent performance across diverse applications,holds significant promise.Herein,we present a proof-of-concept for a high-performance bi-directional Lorentz force magnetometer and actuator,implemented within a single microelectromechanical system(MEMS)device.Moreover,the device demonstrates insensitivity to magnetic fields,making it highly suitable for applications that require anti-crossing behavior in magnetic environments.The design is based on a clamped-guided curved microresonator connected to straight and V-shaped beams of micro-actuators.The operation of the proposed device relies on the flexibility to control the applied electrothermal excitation in different ways,offering smart thermal actuation and dynamic sensing mechanisms.Furthermore,the proposed technique allows tuning of the first symmetric mode,achieving either a high or low frequency shift based on input power levels.Hence,this study provides valuable insights for improving tunability in sensitivity and power for various actuation mechanisms.At atmospheric pressure and an input power of 19.5 mW,the device functions as a high-performance biaxial magnetic sensor with a sensitivity(S)of~36.58%T^(-1),an excellent linearity in the medium-to-high magnetic field range of±400 mT,and a minimum detectable field,Bmin of 0.83μT Hz^(-1).In contrast,it can be tuned as a magnetic-field-insensitive actuator(S=3.28%T^(-1))with a transversal displacement of~4μm,utilizing a negligible power of 43 mW.The diverse operation highlights its hybrid functionality as an actuator or high-performance sensor.These features,combined with the simplicity of fabrication and low cost,make the proposed microdevice highly promising for developing a three-axis magnetic sensor and actuator network system,as well as for various industrial applications.
基金supported by the Korea Medical Device Development Fund grant funded by the Korean government(the Ministry of Science and ICT,the Ministry of Trade,Industry,and Energy,the Ministry of Health&Welfare,and the Ministry of Food and Drug Safety),Grant Number:RS-2020-KD000004National Research Foundation of Korea(NRF)grant funded by the Korean government.Grant Number:2020R1A5A1019649supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea.Grant number:RS-2025-02263957.
文摘Photothermal conversion-based quantitative polymerase chain reaction(qPCR)is a fast,sensitive,and accurate method to diagnose infectious diseases.However,they have bottlenecks in test throughput scalability,cumbersome oil cover,and a lack of multi-target capability.Here,the authors present an infectious disease diagnostic device with rapid photothermal conversion-based efficient reverse transcription(RT)-qPCR assays on a multi-target chip(idreamqPCR).The authors innovate an off-axis mirror-based three-channel fluorescence intensity measurement method,enabling concurrent non-contact temperature control of 16 mini-well reaction chambers for qPCRs without the necessity of actuating parts.A transparent adhesive film on a graphite mixed polydimethylsiloxane(PDMS)-based PCR chip with mini-wells avoids contamination and bubbles to achieve 16 RT-qPCRs(40 photothermal cycles)within 17 min.Finally,idream-qPCR is validated by amplifying severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)N172 bp,RdRP 100 bp,and E 113 bp genes using Fluorescein amidites(FAM),Carboxytetramethylrhodamine(TAMRA),and Cyanine5(CY5)fluorescent dyes,respectively,with 102.5%efficiency and a limit-of-detection(LoD)equivalent to 0.85 copies/μL.idream-qPCR can be efficiently used to prevent the spread of infectious diseases.
