A novel procedure to calibrate the scanning line-structured laser sensor is presented. A drone composed of two orthogonal planes is designed, with the result that camera parameters and light-plane equation parameters ...A novel procedure to calibrate the scanning line-structured laser sensor is presented. A drone composed of two orthogonal planes is designed, with the result that camera parameters and light-plane equation parameters is achieved simultaneously.展开更多
Measurement precision of laser displacement sensor is subject to various factors,among which laser jitter and target tilt will directly lead to the position movement and shape variation of the laser spot,resulting in ...Measurement precision of laser displacement sensor is subject to various factors,among which laser jitter and target tilt will directly lead to the position movement and shape variation of the laser spot,resulting in displacement measurement errors,so that researchers have to do a lot of research on the spot centering algorithm to weaken the above effects,which can treat the symptoms but not the root cause.Starting from the source of the problem,this paper proposes a double focus double peak solution,which uses a reflector to change the direction of the optical path,so that the imaging spots of the designed two optical paths focus on the same CMOS,forming a double peak structure.When laser jitter or target tilt occurs,the center of the two laser spots is shifted,but they move in the same direction,while their relative position remains unchanged.Therefore,the displacement can be characterized by the relative position of the two laser spots,so that laser jitter and target tilt are suppressed from the source.However,the two spots imaged on CMOS form a non-Gaussian distributed double peak structure,so the conventional laser spot centering algorithms are no longer applicable.To this end,a double peak adaptive threshold waveform extraction method combined with grayscale gravity method is proposed for spot centering algorithm,which combines the suppression of laser jitter and target tilt from the source and the improvement of spot positioning precision which represents the displacement measurement precision,and is experimentally verified.展开更多
The laser-assisted manufacturing technology has significant advantages in meeting various demands such as complex structures,functional integration,customized devices,and cost-effectiveness,which makes it a highly att...The laser-assisted manufacturing technology has significant advantages in meeting various demands such as complex structures,functional integration,customized devices,and cost-effectiveness,which makes it a highly attractive option for fabricating sensors.In this review,the latest advancements and strategies in intelligent sensor development through laser processing were surveyed and outlined following the interaction of laser and materials.Laser-assisted manufacturing technologies have been extensively applied in materials science and device processing.Firstly,laser technology can be utilized in a wide range of materials,encompassing carbon-based materials,metals,and metallic oxides.In the field of device scale processing,laser manufacturing is widely used in micro/nano structures,planar device construction,and stereoscopic electronic devices such as cutting,engraving,and lithography.Additionally,laser technology provides robust support for sensor applications,covering fields such as pressure sensing,temperature sensing,gas sensing,and biosensors.Furthermore,laser considerably serves in real application areas such as multifunctional sensing systems,actuators,and robots.The widespread application of laser manufacturing technology in sensor platform fabrication offers effective solutions for realizing the miniaturization,multifunctionality,and integration of sensors.展开更多
Extreme environments challenge the structural health monitoring of advanced equipment.In-situ dynamic tracking temperature is of particular value due to its enormous impact on material properties.However,the realizati...Extreme environments challenge the structural health monitoring of advanced equipment.In-situ dynamic tracking temperature is of particular value due to its enormous impact on material properties.However,the realization of such integrated temperature sensors typically requires complicated layer-by-layer molding and sintering processes including additional thermal barrier coatings.Herein,we report a laser-induced in-situ conductive passivation strategy for the fabrication of a thin-film based wide-range temperature sensor.The instantaneous thermal effect of laser irradiation creates crystalline conductive traces in response to temperature variations.Synchronously,it also allows the formation of an amorphous antioxidative layer without necessitating extra protective coatings.Such configuration enables precise real-time sensing across-50℃to 950℃following the Steinhart-Hart equation.It also exhibits durable performance with only 1.2%drift over 20 hours during long-term high-temperature,instant thermal shock,frequent wearing,and severe vibration.This in-situ,facile laser manufacturing strategy holds great promise in structural health monitoring and fault diagnosis for advanced equipment working in extreme environments.展开更多
Artificial sensory systems(ASS)are pivotal to next-generation extended reality technologies,now evolving into flexible platforms for comfortable wear and immersive user experiences,while ensuring high performance and ...Artificial sensory systems(ASS)are pivotal to next-generation extended reality technologies,now evolving into flexible platforms for comfortable wear and immersive user experiences,while ensuring high performance and operational reliability.To address these demands,metal-based nanoparticles(NPs),such as noble metal,oxide,and multi-elemental NPs,have been extensively incorporated into functional materials of sensory and synaptic devices due to their tunable optical,electrical,and chemical properties,enhancing sensory precision,stability,and environmental adaptability.However,traditional NP fabrication methods often involve complex processing,residual contaminants,and scalability issues,limiting their effectiveness in ASS applications.State-of-the-art laser ablation in liquids(LAL)presents a promising alternative,offering scalable production of surfactant-free NPs with customizable physicochemical properties,though their application in electronics remains underexplored.This review delves into the transformative potential of LAL-fabricated NPs in ASS,covering the fundamental mechanisms of LAL,the role of process parameters,the derivative strategies for size modulation,the diversity of metal-based NPs,their applications in sensory and synaptic devices,and the challenges and perspectives for meeting industrial standards.Bridging the gap between LAL and ASS is poised to revolutionize both industrial manufacturing and academic research by offering scalable solutions to overcome intrinsic tradeoffs between flexibility and performance,fostering innovations in human-centric,immersive electronics.展开更多
Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the ente...Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the entertainment,health monitoring, and medical care sectors. In this work,conducting copper electrodes were fabricated onpolydimethylsiloxane as sensitive stretchable microsensors by integrating laser direct writing and transfer printing approaches. The copper electrode was reduced from copper salt using laser writing rather than the general approach of printing with pre-synthesized copper or copper oxide nanoparticles. An electrical resistivity of 96 l X cm was achieved on 40-lm-thick Cu electrodes on flexible substrates. The motion sensing functionality successfully demonstrated a high sensitivity and mechanical robustness.This in situ fabrication method leads to a path toward electronic devices on flexible substrates.展开更多
Functional materials with high viscosity and solid materials have received more and more attentions in flexible pressure sensors,which are inadequate in the most used molding method.Herein,laser direct writing(LDW)met...Functional materials with high viscosity and solid materials have received more and more attentions in flexible pressure sensors,which are inadequate in the most used molding method.Herein,laser direct writing(LDW)method is proposed to fabricate flexible piezoresistive sensors with microstructures on PDMS/MWCNTs composites with an 8%MWCNTs mass fraction.By controlling laser energy,microstructures with different geometries can be obtained,which significantly impacts the performances of the sensors.Subsequently,curved microcones with excellent performance are fabricated under parameters of f=40 kHz and v=150 mm·s^(-1).The sensor exhibits continuous multi-linear sensitivity,ultrahigh original sensitivity of 21.80%kPa^(-1),wide detection range of over 20 kPa,response/recovery time of~100 ms and good cycle stability for more than 1000 times.Besides,obvious resistance variation can be observed when tiny pressure(a peanut of 30 Pa)is applied.Finally,the flexible piezoresistive sensor can be applied for LED brightness controlling,pulse detection and voice recognition.展开更多
Flexible and wearable humidity sensors play a vital role in daily point-of-care diagnosis and noncontact human-machine interactions.However,achieving a facile and high-speed fabrication approach to realizing flexible ...Flexible and wearable humidity sensors play a vital role in daily point-of-care diagnosis and noncontact human-machine interactions.However,achieving a facile and high-speed fabrication approach to realizing flexible humidity sensors remains a challenge.In this work,a wearable capacitive-type Ga_(2)O_(3)/liquid metal-based humidity sensor is demonstrated by a one-step laser direct writing technique.Owing to the photothermal effect of laser,the Ga_(2)O_(3)-wrapped liquid metal particles can be selectively sintered and converted from insulative to conductive traces with a resistivity of 0.19Ω·cm,while the untreated regions serve as active sensing layers in response to moisture changes.Under 95%relative humidity,the humidity sensor displays a highly stable performance along with rapid response and recover time.Utilizing these superior properties,the Ga_(2)O_(3)/liquid metal-based humidity sensor is able to monitor human respiration rate,as well as skin moisture of the palm under different physiological states for healthcare monitoring.展开更多
This paper investigates the influences of a semiconductor laser with narrow linewidth on a fibre-optic distributed disturbance sensor based on Mach-Zehnder interferometer. It establishes an effective numerical model t...This paper investigates the influences of a semiconductor laser with narrow linewidth on a fibre-optic distributed disturbance sensor based on Mach-Zehnder interferometer. It establishes an effective numerical model to describe the noises and linewidth of a semiconductor laser, taking into account their correlations. Simulation shows that frequency noise has great influences on location errors and their relationship is numerically investigated. Accordingly, there is need to determine the linewidth of the laser less than a threshold and obtain the least location errors. Furthermore, experiments are performed by a sensor prototype using three semiconductor lasers with different linewidths, respectively, with polarization maintaining optical fibres and couplers to eliminate the polarization induced noises and fading. The agreement of simulation with experimental results means that the proposed numerical model can make a comprehensive description of the noise behaviour of a semiconductor laser. The conclusion is useful for choosing a laser source for fibre-optic distributed disturbance sensor to achieve optimized location accuracy. What is more, the proposed numerical model can be widely used for analysing influences of semiconductor lasers on other sensing, communication and optical signal processing systems.展开更多
In this article,we review recent advances in the technology of writing fiber Bragg gratings(FBGs)in selected cores of multicore fibers(MCFs)by using femtosecond laser pulses.The writing technology of such a key elemen...In this article,we review recent advances in the technology of writing fiber Bragg gratings(FBGs)in selected cores of multicore fibers(MCFs)by using femtosecond laser pulses.The writing technology of such a key element as the FBG opens up wide opportunities for the creation of next generation fiber lasers and sensors based on MCFs.The advantages of the technology are shown by using the examples of 3D shape sensors,acoustic emission sensors with spatially multiplexed channels,as well as multicore fiber Raman lasers.展开更多
We report the direct joining of carbon nanofibers(CNFs)to silver nanowire(Ag NWs)by controlled irradiation with femtosecond(fs)laser pulses.Two separate types of nano-junction dependent on joint geometry,laser fluence...We report the direct joining of carbon nanofibers(CNFs)to silver nanowire(Ag NWs)by controlled irradiation with femtosecond(fs)laser pulses.Two separate types of nano-junction dependent on joint geometry,laser fluence and irradiation time are identified in irradiated mixtures.In one type of junction,the tip of an Ag NW is melted and flows to form a bond with an adjacent CNF.The second type of junction occurs without significant heating of the Ag NW and involves the softening and flow of carbon in the CNF in response to the transfer of plasmonic energy from the Ag NW into the CNF.Bonding in a T-type joint configuration can be of either kind depending on the relative orientation of the incident optical field and the long axis of the Ag NW.FDTD simulations were used to explore this effect for different joint geometries and laser polarization.The electrical properties of a heterojunction involving a single Ag NW-CNF structure have been measured,and it is found that the junction resistance can be reduced by six orders of magnitude after laser joining.Finally,we have investigated the properties of a strain sensor based on an Ag NW-CNF hybrid nanowire network and find that this device can exhibit high sensitivity.This sensitivity occurs as nano-junctions induced by fs laser irradiation greatly reduces the initial resistance.This laser-based technique for direct nanojoining of CNF and Ag NWs may enable the design of robust nanowire structures for application in a variety of new devices.展开更多
In order to implement 3D scanning of those complicated parts such as blades in the aviation field,a non-contact optical measuring system is established in the paper,which integrates a laser displacement sensor,a probe...In order to implement 3D scanning of those complicated parts such as blades in the aviation field,a non-contact optical measuring system is established in the paper,which integrates a laser displacement sensor,a probe head,the frame of a coordinate measuring machine（CMM）,etc.As the output of the laser sensor directly obtained possesses the 1D length of the laser beam,it needs to determine the unit direction vector of the laser beam denoted as（l,m,n）by calibration so as to convert the 1D values into 3D coordinates of target points.Therefore,an extrinsic calibration method based on a standard sphere is proposed to accomplish this task in the paper.During the calibration procedure,the laser sensor moves along with the motion of the CMM and gathers the required data on the spherical surface.Then,both the output of the laser sensor and the grating readings of the CMM are substituted into the constraint equation of the spherical surface,in which an over-determined nonlinear equation group containing unknown parameters is established.For the purpose of solving the equation group,a method based on non-linear least squares optimization is put forward.Finally,the system after calibration is utilized to measure the diameter of a metallic sphere 10 times from different orientations to verify the calibration accuracy.In the experiment,the errors between the measured results and the true values are all smaller than 0.03 mm,which manifests the validity and practicality of the extrinsic calibration method presented in the paper.展开更多
Marine resource exploitation and marine cargo transportation were increasingly frequent. Due to the impact of the marine environment, ships or platforms were affected. In this paper, a servo electric cylinder was used...Marine resource exploitation and marine cargo transportation were increasingly frequent. Due to the impact of the marine environment, ships or platforms were affected. In this paper, a servo electric cylinder was used as a wave compensation actuator to design a wave compensation system. The laser sensor was used to measure the displacement in the direction of the heave platform, and the obtained displacement was applied to the wave compensation in the heave direction to verify the feasibility of the compensation system.展开更多
The femtosecond laser has emerged as a powerful tool for micro-and nanoscale device fabrication. Through nonlinear ionization processes, nanometer-sized material modifications can be inscribed in transparent materials...The femtosecond laser has emerged as a powerful tool for micro-and nanoscale device fabrication. Through nonlinear ionization processes, nanometer-sized material modifications can be inscribed in transparent materials for device fabrication. This paper describes femtosecond precision inscription of nanograting in silica fiber cores to form both distributed and point fiber sensors for sensing applications in extreme environmental conditions. Through the use of scanning electron microscope imaging and laser processing optimization,high-temperature stable, Type II femtosecond laser modifications were continuously inscribed,point by point, with only an insertion loss at 1 d B m~(-1) or 0.001 d B per point sensor device.High-temperature performance of fiber sensors was tested at 1000℃, which showed a temperature fluctuation of ±5.5℃ over 5 days. The low laser-induced insertion loss in optical fibers enabled the fabrication of a 1.4 m, radiation-resilient distributed fiber sensor. The in-pile testing of the distributed fiber sensor further showed that fiber sensors can execute stable and distributed temperature measurements in extreme radiation environments. Overall, this paper demonstrates that femtosecond-laser-fabricated fiber sensors are suitable measurement devices for applications in extreme environments.展开更多
An on-machine measuring(OMM)system with a laser displacement sensor(LDS)is designed for measuring free-form surfaces of hypersonic aircraft’s radomes.To improve the measurement accuracy of the OMM system,a novel Iter...An on-machine measuring(OMM)system with a laser displacement sensor(LDS)is designed for measuring free-form surfaces of hypersonic aircraft’s radomes.To improve the measurement accuracy of the OMM system,a novel Iteratively Automatic machine learning Boosted hand-eye Calibration(IABC)method is proposed.Both the hand-eye relationship and LDS measurement errors can be calibrated in one calibration process without any hardware changes via IABC.Firstly,a new objective function is derived,containing analytical parameters of the handeye relationship and LDS errors.Then,a hybrid calibration model composed of two kernels is proposed to solve the objective function.One kernel is the analytical kernel designed for solving analytical parameters.Another kernel is the automatic machine learning(AutoML)kernel designed to model LDS errors.The two kernels are connected with stepwise iterations to find the best calibration results.Compared with traditional methods,hand-eye experiments show that IABC reduces the calibration RMSE by about 50%.Verification experiments show that IABC reduces the measurement deviations by about 25%-50%and RMSEs within 40%.Even when the training data are obviously less than the test data,IABC performs well.Experiments demonstrate that IABC is more accurate than traditional hand-eye methods.展开更多
An NO2 photoacoustic sensor system with a high reflective mirror based on a low power blue diode laser is developed in this work. The excitation power is enhanced by increasing the number of reflections. Comparing wit...An NO2 photoacoustic sensor system with a high reflective mirror based on a low power blue diode laser is developed in this work. The excitation power is enhanced by increasing the number of reflections. Comparing with a traditional photoacoustic system, the pool constant is improved from 300.24(Pa·cm)/W to 1450.64(Pa·cm)/W, and the signal sensitivity of the photoacoustic sensor is increased from 0.016 μV/ppb to 0.2562 μV/ppb. The characteristics of temperature and humidity of the new photoacoustic sensor are also obtained, and the algorithm is adjusted to provide a quantitative response and drift of the resonance frequency. The results of this research provide a new method and concept for further developing the NO2 photoacoustic sensors.展开更多
A twist sensor with hybrid few-mode tilted fiber Bragg grating(FM-TFBG) and few-mode long period grating(FM-LPG) in fiber laser cavity is demonstrated. The FM-LPG is utilized to excite LP11 core mode. The FM-TFBG is u...A twist sensor with hybrid few-mode tilted fiber Bragg grating(FM-TFBG) and few-mode long period grating(FM-LPG) in fiber laser cavity is demonstrated. The FM-LPG is utilized to excite LP11 core mode. The FM-TFBG is used for sensing. The transverse modes at 1 553.9 nm and 1 550.5 nm are LP01 and LP21 core modes, respectively, which are coupled from forward-propagating LP11 core mode. These two excitation wavelengths have opposite variation tendencies, which participate in sensing. The twist sensitivity of 0.16 dB/° from-40° to 40° is achieved. The proposed sensor has potentially used for structure monitoring in many areas.展开更多
Measuring and reconstructing the shape of workpieces have been considered as a fundamental step in both reverse engineering and product quality control.Owing to increasing structural complexity of recent products,meas...Measuring and reconstructing the shape of workpieces have been considered as a fundamental step in both reverse engineering and product quality control.Owing to increasing structural complexity of recent products,measurements from multiple directions are typically required in current scanning techniques.Specifically,the plane structured light can be applied to measure one area of a part at a time,with an additional algorithm required to merge the collected data of each area.Alternatively,the line structured light sensor integrated on CNC machines or CMMs could also realize multi-view measurement.However,the system needs to be repeatedly calibrated at each new direction.This paper presents a flexible scanning method by integrating laser line sensors with articulated arm coordinate measuring machines(AACMM).Since the output of the laser line sensor is 2D raw data in the laser plane,our system model introduces an explicit transformation from the 2D sensor coordinate frame to the 3D base coordinate frame of the AACMM(i.e.,the translation and rotation the of the 2D sensor coordinate in the sixth coordinate system of AACMM).To solve the model,the“conjugate pairs”are proposed and identified by measuring a fixed point(e.g.,a sphere center).Moreover,a search algorithm is adopted to find the optimal solution,which noticeably boosts the model accuracy.The experimental results show that the error of the system is about 0.2 mm,which is caused by the error of the AACMM,the sensor error and the calibration error.By measuring a complicated part,the proposed system is proved to be flexible and facilitate,with the ability to measure a part expediently from any necessary direction.Furthermore,the proposed calibration method can also be used for robot hand-eye relationship calibration.展开更多
Perovskite oxides like S rTiO_(3) at the nanoscale are of interest for eme rging applications,including high-k dielectrics and sensors.However,their synthesis requires long calcination at the elevated temperature,whic...Perovskite oxides like S rTiO_(3) at the nanoscale are of interest for eme rging applications,including high-k dielectrics and sensors.However,their synthesis requires long calcination at the elevated temperature,which is a barrier of their application to flexible electronics.Here,an effective laser-assisted sol-gel method to patternably produce S rTiO_(3) na noparticles(-100 nm)in selective areas on polyimide substrates(coated with ITO)is introduced.Importantly,the violet-laser power is just 1 W but sufficient to crystallize the material in a short period(a few seconds).Furthermore,developing a flexible device platform using carbon nanotubes(CNT)and SrTiO_(3) nanoparticles for detection of humidity changes at room temperature is proposed.The sensor platform has both capacitive and resistive sensing abilities.The resistive mode with a lower power usage(about 0.2μW)is suitable for long monitoring of humidity in the range of2%RH and above.The capacitive mode with higher sensitivity,faster response/recovery time(1-3 min),and lower detection limit(0.5%RH)can be used for calibration purposes.The performance of the flexible sensor is still maintained after 5000 bending cycles at 1.5-cm radius.Altogether,our synthesis method and the flexible sensor show chances for mass-producing perovskite oxides at low cost for wearable electronics.展开更多
Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are ur...Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are urgent.Here,another 2D material,violet phosphorus(VP)nanoflake is investigated as gas sensing material.The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol.The VP nanoflakes are combined with graphene to form VP/G heterostructuresbased NO sensor.An ultra-high gauge factor of 3×10^(7)for ppb-level sensing and high resistance response of 59.21%with ultra-short recovery time of 6s for ppm-level sensing have been obtained.The sensing mechanism is also analysed by density functional theory(DFT)calculations.The adsorption energy of VP/G is calculated to be-0.788 e V,resulting in electrons migration from P to N to form a P-N bond in the gap between VP and graphene sheet.This work provides a facile approach to ablate VP for mass production.The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.展开更多
文摘A novel procedure to calibrate the scanning line-structured laser sensor is presented. A drone composed of two orthogonal planes is designed, with the result that camera parameters and light-plane equation parameters is achieved simultaneously.
基金the Biomedical Science and Technology Support Special Project of Shanghai Science and Technology Committee(No.20S31908300)。
文摘Measurement precision of laser displacement sensor is subject to various factors,among which laser jitter and target tilt will directly lead to the position movement and shape variation of the laser spot,resulting in displacement measurement errors,so that researchers have to do a lot of research on the spot centering algorithm to weaken the above effects,which can treat the symptoms but not the root cause.Starting from the source of the problem,this paper proposes a double focus double peak solution,which uses a reflector to change the direction of the optical path,so that the imaging spots of the designed two optical paths focus on the same CMOS,forming a double peak structure.When laser jitter or target tilt occurs,the center of the two laser spots is shifted,but they move in the same direction,while their relative position remains unchanged.Therefore,the displacement can be characterized by the relative position of the two laser spots,so that laser jitter and target tilt are suppressed from the source.However,the two spots imaged on CMOS form a non-Gaussian distributed double peak structure,so the conventional laser spot centering algorithms are no longer applicable.To this end,a double peak adaptive threshold waveform extraction method combined with grayscale gravity method is proposed for spot centering algorithm,which combines the suppression of laser jitter and target tilt from the source and the improvement of spot positioning precision which represents the displacement measurement precision,and is experimentally verified.
基金supported by National Key Research and Development Program of China(2023YFB3210400)the National Natural Science Foundation of China(52472097 and 52102171)+2 种基金Natural Science Foundation of Shandong Province(ZR2021JQ15,ZR2023LLZ008 and ZR2022YQ42)Taishan Scholar Project of Shandong Province(tstp20240515)Innovative Team Project of Jinan(2021GXRC019).
文摘The laser-assisted manufacturing technology has significant advantages in meeting various demands such as complex structures,functional integration,customized devices,and cost-effectiveness,which makes it a highly attractive option for fabricating sensors.In this review,the latest advancements and strategies in intelligent sensor development through laser processing were surveyed and outlined following the interaction of laser and materials.Laser-assisted manufacturing technologies have been extensively applied in materials science and device processing.Firstly,laser technology can be utilized in a wide range of materials,encompassing carbon-based materials,metals,and metallic oxides.In the field of device scale processing,laser manufacturing is widely used in micro/nano structures,planar device construction,and stereoscopic electronic devices such as cutting,engraving,and lithography.Additionally,laser technology provides robust support for sensor applications,covering fields such as pressure sensing,temperature sensing,gas sensing,and biosensors.Furthermore,laser considerably serves in real application areas such as multifunctional sensing systems,actuators,and robots.The widespread application of laser manufacturing technology in sensor platform fabrication offers effective solutions for realizing the miniaturization,multifunctionality,and integration of sensors.
基金the financial support from the National Natural Science Foundation of China(52475610,52105593)the Zhejiang Provincial Natural Science Foundation of China(LDQ24E050001)+1 种基金the"Pioneer"and"Leading Goose"R&D Program of Zhejiang(2023C03007,2024C01173)the Fundamental Research Funds for the Central Universities(226-2024-00085)。
文摘Extreme environments challenge the structural health monitoring of advanced equipment.In-situ dynamic tracking temperature is of particular value due to its enormous impact on material properties.However,the realization of such integrated temperature sensors typically requires complicated layer-by-layer molding and sintering processes including additional thermal barrier coatings.Herein,we report a laser-induced in-situ conductive passivation strategy for the fabrication of a thin-film based wide-range temperature sensor.The instantaneous thermal effect of laser irradiation creates crystalline conductive traces in response to temperature variations.Synchronously,it also allows the formation of an amorphous antioxidative layer without necessitating extra protective coatings.Such configuration enables precise real-time sensing across-50℃to 950℃following the Steinhart-Hart equation.It also exhibits durable performance with only 1.2%drift over 20 hours during long-term high-temperature,instant thermal shock,frequent wearing,and severe vibration.This in-situ,facile laser manufacturing strategy holds great promise in structural health monitoring and fault diagnosis for advanced equipment working in extreme environments.
基金supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science and ICT(Grant Nos.RS-2024-00403639 and RS2024-00411904)。
文摘Artificial sensory systems(ASS)are pivotal to next-generation extended reality technologies,now evolving into flexible platforms for comfortable wear and immersive user experiences,while ensuring high performance and operational reliability.To address these demands,metal-based nanoparticles(NPs),such as noble metal,oxide,and multi-elemental NPs,have been extensively incorporated into functional materials of sensory and synaptic devices due to their tunable optical,electrical,and chemical properties,enhancing sensory precision,stability,and environmental adaptability.However,traditional NP fabrication methods often involve complex processing,residual contaminants,and scalability issues,limiting their effectiveness in ASS applications.State-of-the-art laser ablation in liquids(LAL)presents a promising alternative,offering scalable production of surfactant-free NPs with customizable physicochemical properties,though their application in electronics remains underexplored.This review delves into the transformative potential of LAL-fabricated NPs in ASS,covering the fundamental mechanisms of LAL,the role of process parameters,the derivative strategies for size modulation,the diversity of metal-based NPs,their applications in sensory and synaptic devices,and the challenges and perspectives for meeting industrial standards.Bridging the gap between LAL and ASS is poised to revolutionize both industrial manufacturing and academic research by offering scalable solutions to overcome intrinsic tradeoffs between flexibility and performance,fostering innovations in human-centric,immersive electronics.
基金supported by National Natural Science Foundation of China (51575016)the Beijing Oversea High-Level Talent Project+1 种基金strategic research Grant (KZ20141000500, B-type) of Beijing Natural Science Foundation P.R. Chinathe support by the China Scholarship Council (20160654015) for his research stay at the Institute of Physical and Chemical Research,Wako, Japan
文摘Stretchable electronic sensing devices are defining the path toward wearable electronics. High-performance flexible strain sensors attached on clothing or human skin are required for potential applications in the entertainment,health monitoring, and medical care sectors. In this work,conducting copper electrodes were fabricated onpolydimethylsiloxane as sensitive stretchable microsensors by integrating laser direct writing and transfer printing approaches. The copper electrode was reduced from copper salt using laser writing rather than the general approach of printing with pre-synthesized copper or copper oxide nanoparticles. An electrical resistivity of 96 l X cm was achieved on 40-lm-thick Cu electrodes on flexible substrates. The motion sensing functionality successfully demonstrated a high sensitivity and mechanical robustness.This in situ fabrication method leads to a path toward electronic devices on flexible substrates.
基金supported by the National Natural Science Foundation of China(No.51922092,No.51705439)Domain Foundation of Equipment Advance Research of 13th Five-year Plan(JZX7Y20190243000801)+1 种基金the Natural Science Foundation of Fujian Province of China(No.2017J06015)Science and Technology Plan Project of Xiamen City(No.3502Z20173024).
文摘Functional materials with high viscosity and solid materials have received more and more attentions in flexible pressure sensors,which are inadequate in the most used molding method.Herein,laser direct writing(LDW)method is proposed to fabricate flexible piezoresistive sensors with microstructures on PDMS/MWCNTs composites with an 8%MWCNTs mass fraction.By controlling laser energy,microstructures with different geometries can be obtained,which significantly impacts the performances of the sensors.Subsequently,curved microcones with excellent performance are fabricated under parameters of f=40 kHz and v=150 mm·s^(-1).The sensor exhibits continuous multi-linear sensitivity,ultrahigh original sensitivity of 21.80%kPa^(-1),wide detection range of over 20 kPa,response/recovery time of~100 ms and good cycle stability for more than 1000 times.Besides,obvious resistance variation can be observed when tiny pressure(a peanut of 30 Pa)is applied.Finally,the flexible piezoresistive sensor can be applied for LED brightness controlling,pulse detection and voice recognition.
基金This study was supported by the National Natural Science Foundation of China (52105593 and 62271439)STI 2030 —Major Projects(2022ZD0208601)the “Pioneer” and “Leading Goose” R&D Program of Zhejiang (2023C01051)。
文摘Flexible and wearable humidity sensors play a vital role in daily point-of-care diagnosis and noncontact human-machine interactions.However,achieving a facile and high-speed fabrication approach to realizing flexible humidity sensors remains a challenge.In this work,a wearable capacitive-type Ga_(2)O_(3)/liquid metal-based humidity sensor is demonstrated by a one-step laser direct writing technique.Owing to the photothermal effect of laser,the Ga_(2)O_(3)-wrapped liquid metal particles can be selectively sintered and converted from insulative to conductive traces with a resistivity of 0.19Ω·cm,while the untreated regions serve as active sensing layers in response to moisture changes.Under 95%relative humidity,the humidity sensor displays a highly stable performance along with rapid response and recover time.Utilizing these superior properties,the Ga_(2)O_(3)/liquid metal-based humidity sensor is able to monitor human respiration rate,as well as skin moisture of the palm under different physiological states for healthcare monitoring.
文摘This paper investigates the influences of a semiconductor laser with narrow linewidth on a fibre-optic distributed disturbance sensor based on Mach-Zehnder interferometer. It establishes an effective numerical model to describe the noises and linewidth of a semiconductor laser, taking into account their correlations. Simulation shows that frequency noise has great influences on location errors and their relationship is numerically investigated. Accordingly, there is need to determine the linewidth of the laser less than a threshold and obtain the least location errors. Furthermore, experiments are performed by a sensor prototype using three semiconductor lasers with different linewidths, respectively, with polarization maintaining optical fibres and couplers to eliminate the polarization induced noises and fading. The agreement of simulation with experimental results means that the proposed numerical model can make a comprehensive description of the noise behaviour of a semiconductor laser. The conclusion is useful for choosing a laser source for fibre-optic distributed disturbance sensor to achieve optimized location accuracy. What is more, the proposed numerical model can be widely used for analysing influences of semiconductor lasers on other sensing, communication and optical signal processing systems.
基金supported by the Russian Ministry of Science and Higher Education (14.Y26.31.0017)Russian Foundation for Basic Research(18-52-7822)the work concerning MCF fiber Raman lasers was supported by Russian Science Foundation (21-72-30024)
文摘In this article,we review recent advances in the technology of writing fiber Bragg gratings(FBGs)in selected cores of multicore fibers(MCFs)by using femtosecond laser pulses.The writing technology of such a key element as the FBG opens up wide opportunities for the creation of next generation fiber lasers and sensors based on MCFs.The advantages of the technology are shown by using the examples of 3D shape sensors,acoustic emission sensors with spatially multiplexed channels,as well as multicore fiber Raman lasers.
基金financially supported by the National Natural Science Foundation of China(No.U1730107)the National Natural Science Foundation of China(No.51522503)+2 种基金the Program for New Century Excellent Talents in University(No.NCET-13-0175)the Natural Sciences and Engineering Research Council(NSERC)of Canada and Canada Research Chairs(CRC)Programsthe China Scholarship Council(CSC)for the graduate fellowship。
文摘We report the direct joining of carbon nanofibers(CNFs)to silver nanowire(Ag NWs)by controlled irradiation with femtosecond(fs)laser pulses.Two separate types of nano-junction dependent on joint geometry,laser fluence and irradiation time are identified in irradiated mixtures.In one type of junction,the tip of an Ag NW is melted and flows to form a bond with an adjacent CNF.The second type of junction occurs without significant heating of the Ag NW and involves the softening and flow of carbon in the CNF in response to the transfer of plasmonic energy from the Ag NW into the CNF.Bonding in a T-type joint configuration can be of either kind depending on the relative orientation of the incident optical field and the long axis of the Ag NW.FDTD simulations were used to explore this effect for different joint geometries and laser polarization.The electrical properties of a heterojunction involving a single Ag NW-CNF structure have been measured,and it is found that the junction resistance can be reduced by six orders of magnitude after laser joining.Finally,we have investigated the properties of a strain sensor based on an Ag NW-CNF hybrid nanowire network and find that this device can exhibit high sensitivity.This sensitivity occurs as nano-junctions induced by fs laser irradiation greatly reduces the initial resistance.This laser-based technique for direct nanojoining of CNF and Ag NWs may enable the design of robust nanowire structures for application in a variety of new devices.
基金supported by the National Science and Technology Major Project for ‘‘High-grade Numerical Control Machine Tools and Basic Manufacturing Equipment” of China (No. 2013ZX04001071)
文摘In order to implement 3D scanning of those complicated parts such as blades in the aviation field,a non-contact optical measuring system is established in the paper,which integrates a laser displacement sensor,a probe head,the frame of a coordinate measuring machine（CMM）,etc.As the output of the laser sensor directly obtained possesses the 1D length of the laser beam,it needs to determine the unit direction vector of the laser beam denoted as（l,m,n）by calibration so as to convert the 1D values into 3D coordinates of target points.Therefore,an extrinsic calibration method based on a standard sphere is proposed to accomplish this task in the paper.During the calibration procedure,the laser sensor moves along with the motion of the CMM and gathers the required data on the spherical surface.Then,both the output of the laser sensor and the grating readings of the CMM are substituted into the constraint equation of the spherical surface,in which an over-determined nonlinear equation group containing unknown parameters is established.For the purpose of solving the equation group,a method based on non-linear least squares optimization is put forward.Finally,the system after calibration is utilized to measure the diameter of a metallic sphere 10 times from different orientations to verify the calibration accuracy.In the experiment,the errors between the measured results and the true values are all smaller than 0.03 mm,which manifests the validity and practicality of the extrinsic calibration method presented in the paper.
文摘Marine resource exploitation and marine cargo transportation were increasingly frequent. Due to the impact of the marine environment, ships or platforms were affected. In this paper, a servo electric cylinder was used as a wave compensation actuator to design a wave compensation system. The laser sensor was used to measure the displacement in the direction of the heave platform, and the obtained displacement was applied to the wave compensation in the heave direction to verify the feasibility of the compensation system.
基金supported in part through Department of Energy Grants DE-NE0008686 and DE-FE00028992the NEET ASI program under DOE Idaho Operations Office Contract DE-AC07-05ID14517。
文摘The femtosecond laser has emerged as a powerful tool for micro-and nanoscale device fabrication. Through nonlinear ionization processes, nanometer-sized material modifications can be inscribed in transparent materials for device fabrication. This paper describes femtosecond precision inscription of nanograting in silica fiber cores to form both distributed and point fiber sensors for sensing applications in extreme environmental conditions. Through the use of scanning electron microscope imaging and laser processing optimization,high-temperature stable, Type II femtosecond laser modifications were continuously inscribed,point by point, with only an insertion loss at 1 d B m~(-1) or 0.001 d B per point sensor device.High-temperature performance of fiber sensors was tested at 1000℃, which showed a temperature fluctuation of ±5.5℃ over 5 days. The low laser-induced insertion loss in optical fibers enabled the fabrication of a 1.4 m, radiation-resilient distributed fiber sensor. The in-pile testing of the distributed fiber sensor further showed that fiber sensors can execute stable and distributed temperature measurements in extreme radiation environments. Overall, this paper demonstrates that femtosecond-laser-fabricated fiber sensors are suitable measurement devices for applications in extreme environments.
基金supported by the National Natural Science Foundation of China (Nos. 51875406 and 51805365)
文摘An on-machine measuring(OMM)system with a laser displacement sensor(LDS)is designed for measuring free-form surfaces of hypersonic aircraft’s radomes.To improve the measurement accuracy of the OMM system,a novel Iteratively Automatic machine learning Boosted hand-eye Calibration(IABC)method is proposed.Both the hand-eye relationship and LDS measurement errors can be calibrated in one calibration process without any hardware changes via IABC.Firstly,a new objective function is derived,containing analytical parameters of the handeye relationship and LDS errors.Then,a hybrid calibration model composed of two kernels is proposed to solve the objective function.One kernel is the analytical kernel designed for solving analytical parameters.Another kernel is the automatic machine learning(AutoML)kernel designed to model LDS errors.The two kernels are connected with stepwise iterations to find the best calibration results.Compared with traditional methods,hand-eye experiments show that IABC reduces the calibration RMSE by about 50%.Verification experiments show that IABC reduces the measurement deviations by about 25%-50%and RMSEs within 40%.Even when the training data are obviously less than the test data,IABC performs well.Experiments demonstrate that IABC is more accurate than traditional hand-eye methods.
基金National Natural Science Foundation of China(Grant Nos.91644107,61575206,51904009,and 41905130)National Key Research and Development Program of China(Grant Nos.2017YFC0209401,2017YFC0209403,and 2017YFC0209902)the Outstanding Young Talents Program of Anhui University,China(Grant No.gxyq2019022).
文摘An NO2 photoacoustic sensor system with a high reflective mirror based on a low power blue diode laser is developed in this work. The excitation power is enhanced by increasing the number of reflections. Comparing with a traditional photoacoustic system, the pool constant is improved from 300.24(Pa·cm)/W to 1450.64(Pa·cm)/W, and the signal sensitivity of the photoacoustic sensor is increased from 0.016 μV/ppb to 0.2562 μV/ppb. The characteristics of temperature and humidity of the new photoacoustic sensor are also obtained, and the algorithm is adjusted to provide a quantitative response and drift of the resonance frequency. The results of this research provide a new method and concept for further developing the NO2 photoacoustic sensors.
基金supported by the National Natural Science Foundation of China(Nos.11674177,61775107,61835006 and 11704283)the Natural Science Foundation of Tianjin in China(No.16JCZDJC31000)the Scientific Research Planning and Development Project of Handan in China(No.1621203035)
文摘A twist sensor with hybrid few-mode tilted fiber Bragg grating(FM-TFBG) and few-mode long period grating(FM-LPG) in fiber laser cavity is demonstrated. The FM-LPG is utilized to excite LP11 core mode. The FM-TFBG is used for sensing. The transverse modes at 1 553.9 nm and 1 550.5 nm are LP01 and LP21 core modes, respectively, which are coupled from forward-propagating LP11 core mode. These two excitation wavelengths have opposite variation tendencies, which participate in sensing. The twist sensitivity of 0.16 dB/° from-40° to 40° is achieved. The proposed sensor has potentially used for structure monitoring in many areas.
基金National Natural Science Foundation of China(Grant No.42076192).
文摘Measuring and reconstructing the shape of workpieces have been considered as a fundamental step in both reverse engineering and product quality control.Owing to increasing structural complexity of recent products,measurements from multiple directions are typically required in current scanning techniques.Specifically,the plane structured light can be applied to measure one area of a part at a time,with an additional algorithm required to merge the collected data of each area.Alternatively,the line structured light sensor integrated on CNC machines or CMMs could also realize multi-view measurement.However,the system needs to be repeatedly calibrated at each new direction.This paper presents a flexible scanning method by integrating laser line sensors with articulated arm coordinate measuring machines(AACMM).Since the output of the laser line sensor is 2D raw data in the laser plane,our system model introduces an explicit transformation from the 2D sensor coordinate frame to the 3D base coordinate frame of the AACMM(i.e.,the translation and rotation the of the 2D sensor coordinate in the sixth coordinate system of AACMM).To solve the model,the“conjugate pairs”are proposed and identified by measuring a fixed point(e.g.,a sphere center).Moreover,a search algorithm is adopted to find the optimal solution,which noticeably boosts the model accuracy.The experimental results show that the error of the system is about 0.2 mm,which is caused by the error of the AACMM,the sensor error and the calibration error.By measuring a complicated part,the proposed system is proved to be flexible and facilitate,with the ability to measure a part expediently from any necessary direction.Furthermore,the proposed calibration method can also be used for robot hand-eye relationship calibration.
基金financial support from the National Research Foundation of Korea[NRF–2019R1A2C2003804,2018H1D3A1A02074733,and 2018R1D1A1B07050008]powered by the Ministry of Science and ICT,Republic of Koreasupported by Ajou Universityresults of the study on the¨Leaders in Industry-University Cooperation+Project,supported by the Ministry of Education and National Research Foundation of Korea。
文摘Perovskite oxides like S rTiO_(3) at the nanoscale are of interest for eme rging applications,including high-k dielectrics and sensors.However,their synthesis requires long calcination at the elevated temperature,which is a barrier of their application to flexible electronics.Here,an effective laser-assisted sol-gel method to patternably produce S rTiO_(3) na noparticles(-100 nm)in selective areas on polyimide substrates(coated with ITO)is introduced.Importantly,the violet-laser power is just 1 W but sufficient to crystallize the material in a short period(a few seconds).Furthermore,developing a flexible device platform using carbon nanotubes(CNT)and SrTiO_(3) nanoparticles for detection of humidity changes at room temperature is proposed.The sensor platform has both capacitive and resistive sensing abilities.The resistive mode with a lower power usage(about 0.2μW)is suitable for long monitoring of humidity in the range of2%RH and above.The capacitive mode with higher sensitivity,faster response/recovery time(1-3 min),and lower detection limit(0.5%RH)can be used for calibration purposes.The performance of the flexible sensor is still maintained after 5000 bending cycles at 1.5-cm radius.Altogether,our synthesis method and the flexible sensor show chances for mass-producing perovskite oxides at low cost for wearable electronics.
基金the funding support by National Natural Science Foundation of China(Nos.61705125,22175136)Open Foundation of State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures,Guangxi University(No.2022GXYSOF15)。
文摘Two dimensional(2D)materials are promising gas sensing materials,but the most of them need to be heated to show promising sensing performance.Sensing structures with high sensing performance at room-temperature are urgent.Here,another 2D material,violet phosphorus(VP)nanoflake is investigated as gas sensing material.The VP nanoflakes have been effectively ablated to have layers of 1–5 layers by laser ablation in glycol.The VP nanoflakes are combined with graphene to form VP/G heterostructuresbased NO sensor.An ultra-high gauge factor of 3×10^(7)for ppb-level sensing and high resistance response of 59.21%with ultra-short recovery time of 6s for ppm-level sensing have been obtained.The sensing mechanism is also analysed by density functional theory(DFT)calculations.The adsorption energy of VP/G is calculated to be-0.788 e V,resulting in electrons migration from P to N to form a P-N bond in the gap between VP and graphene sheet.This work provides a facile approach to ablate VP for mass production.The as-produced structures have also provided potential gas sensors with ultrasensitive performance as ppb-level room-temperature sensors.
