This paper presents a 1.2 V high accuracy thermal sensor analog front-end circuit with 7 probes placed around the microprocessor chip.This analog front-end consists of a BGR(bandgap reference),a DEM(dynamic element ma...This paper presents a 1.2 V high accuracy thermal sensor analog front-end circuit with 7 probes placed around the microprocessor chip.This analog front-end consists of a BGR(bandgap reference),a DEM(dynamic element matching)control,and probes.The BGR generates the voltages linear changed with temperature,which are followed by the data read out circuits.The superior accuracy of the BGR’s output voltage is a key factor for sensors fabricated via the FinFET digital process.Here,a 4-stage folded current bias structure is proposed,to increase DC accuracy and confer immunity against FinFET process variation due to limited device length and low current bias.At the same time,DEM is also adopted,so as to filter out current branch mismatches.Having been fabricated via a 12 nm FinFET CMOS process,200 chips were tested.The measurement results demonstrate that these analog front-end circuits can work steadily below 1.2 V,and a less than 3.1%3σ-accuracy level is achieved.Temperature stability is 0.088 mV/℃across a range from-40 to 130℃.展开更多
Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexib...Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexible fiber sensors.Through the preform-tofiber manufacturing technique,a variety of fiber sensors with complex functionalities spanning from the nanoscale to kilometer scale can be automated in a short time.Examples include temperature,acoustic,mechanical,chemical,biological,optoelectronic,and multifunctional sensors,which operate on diverse sensing principles such as resistance,capacitance,piezoelectricity,triboelectricity,photoelectricity,and thermoelectricity.This review outlines the principles of the thermal drawing process and provides a detailed overview of the latest advancements in various thermally drawn fiber sensors.Finally,the future developments of thermally drawn fiber sensors are discussed.展开更多
The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate （MHP） and operating...The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate （MHP） and operating under constant bias voltage conditions was designed. A new monolithic integrating mode was proposed,in which the dielectric and passiva- tion layers in standard CMOS processes were used as sensor structure layers,gate polysilicon as the sacrificial layer,and the second polysilicon layer as the sensor heating resistor. Then, the fabricating processes were designed and the monolithic thermal vacuum sensor was fabricated with a 0. 6μm mixed signal CMOS process followed by sacrificial layer etching technology. The measurement results show that the fabricated monolithic vacuum sensor can measure the pressure range of 2- 10^5 Pa and the output voltage is adjustable.展开更多
With the characteristic size reducing as well as the power densities exponentially increasing, elevated chip temperatures are true limiters to the performance and reliability of integrated circuits. To address these t...With the characteristic size reducing as well as the power densities exponentially increasing, elevated chip temperatures are true limiters to the performance and reliability of integrated circuits. To address these thermal issues, it is essential to use a set of on-chip thermal sensors to monitor temperatures during operation.These temperature sampling results are then used by thermal management techniques to appropriately manage chip performance. In this paper, we propose a surface spline interpolation method to reconstruct the full thermal characterization of integrated circuits with non-uniform thermal sensor placements. We construct the thermal surface function using the mathematical tool of surface spline with the matrix calculation of the non-uniform sample data. Then, we take the coordinates of the points at grid locations into the surface function to get its temperature value so that we can reconstruct the full thermal signals. To evaluate the effiectiveness of our method,we develop an experiment for reconstructing full thermal status of a 16-core processor. Experimental results show that our method outperforms the inverse distance weighting method based on dynamic Voronoi diagram and spectral analysis techniques both in the average absolute error metric and the hot spot absolute error metric with short enough runtime to meet the real-time process demand. Besides, our method still has the advantages such as its mathematical simplicity with no need of pre-process.展开更多
Using embedded thermal sensors, dynamic thermal management(DTM) techniques measure runtime thermal behavior of high-performance microprocessors so as to prevent thermal runaway situations. The number of placed sensors...Using embedded thermal sensors, dynamic thermal management(DTM) techniques measure runtime thermal behavior of high-performance microprocessors so as to prevent thermal runaway situations. The number of placed sensors should be minimized, while guaranteeing accurate tracking of hot spots and full thermal characterization. In this paper, we propose a rigid sensor allocation and placement technique for determining the minimal number of thermal sensors and the optimal locations while satisfying an expected accuracy of hot spot temperature error based on dual clustering. We analyze the false alarm rates of hot spots using the proposed methods in noise-free, with noise and sensor calibration scenarios, respectively. Experimental results confirm that our proposed methods are capable of accurately characterizing the temperatures of microprocessors.展开更多
Low Resolution Thermal Array Sensors are widely used in several applications in indoor environments. In particular, one of these cheap, small and unobtrusive sensors provides a low-resolution thermal image of the envi...Low Resolution Thermal Array Sensors are widely used in several applications in indoor environments. In particular, one of these cheap, small and unobtrusive sensors provides a low-resolution thermal image of the environment and, unlike cameras;it is capable to detect human heat emission even in dark rooms. The obtained thermal data can be used to monitor older seniors while they are performing daily activities at home, to detect critical situations such as falls. Most of the studies in activity recognition using Thermal Array Sensors require human detection techniques to recognize humans passing in the sensor field of view. This paper aims to improve the accuracy of the algorithms used so far by considering the temperature environment variation. This method leverages an adaptive background estimation and a noise removal technique based on Kalman Filter. In order to properly validate the system, a novel installation of a single sensor has been implemented in a smart environment: the obtained results show an improvement in human detection accuracy with respect to the state of the art, especially in case of disturbed environments.展开更多
According to the sensing structure of a practical silicon resonant pressure micro sensor whose preliminary sensing unit is a square silicon diaphragm and the final sensing unit is a silicon beam resonator, its operati...According to the sensing structure of a practical silicon resonant pressure micro sensor whose preliminary sensing unit is a square silicon diaphragm and the final sensing unit is a silicon beam resonator, its operating mechanism is analyzed. The thermal resistor acts as the excited unit, and the piezoresistive unit acts as the detector, for the above micro sensor. By using the amplitude and phase conditions, the self exciting closed loop system is investigated based on the operating mechanism for the abov...展开更多
A thermal sensor for material identification is proposed. This paper describes the model,design, and testing of the sensor. Some factors of the detector which affect the performancesof the sensor are discussed. A new ...A thermal sensor for material identification is proposed. This paper describes the model,design, and testing of the sensor. Some factors of the detector which affect the performancesof the sensor are discussed. A new concept called the thermal sense characteristic parameter isadvanced, and the relationship between the thermal sense characteristic parameter and theresponse of the sensor is given. A method for computing thermal sense characteristic param-eter from the response of the sensor is indicated. Based on our developed sensor, the correc-tion rates of the testing results of the seven materials (copper, aluminum, steel, rubber, PCB,polyflon, paper) from 130 identifications are 100%.展开更多
This paper describes a micro thermal shear stress sensor with a cavity underneath, based on vacuum anodic bonding and bulk micromachined technology. A Ti/Pt alloy strip, 2μm×100μm, is deposited on the top of a ...This paper describes a micro thermal shear stress sensor with a cavity underneath, based on vacuum anodic bonding and bulk micromachined technology. A Ti/Pt alloy strip, 2μm×100μm, is deposited on the top of a thin silicon nitride diaphragm and functioned as the thermal sensor element. By using vacuum anodic bonding and bulk-si anisotropic wet etching process instead of the sacrificial-layer technique, a cavity, functioned as the adiabatic vacuum chamber, 200μm×200μm×400μm, is placed between the silicon nitride diaphragm and glass （Corning 7740）. This method totally avoid adhesion problem which is a major issue of the sacrificial-layer technique.展开更多
Luminescent materials for application in temperature sensing have caught a lot of interest in recent years.Particularly erbium(Er^(3+))-doped fluoride-based materials(EFM),which are readily accessible by near-infrared...Luminescent materials for application in temperature sensing have caught a lot of interest in recent years.Particularly erbium(Er^(3+))-doped fluoride-based materials(EFM),which are readily accessible by near-infrared(NIR)excitation to produce efficient photon conversion.It has been established that ytterbium(Yb^(3+))may improve the performance of EFMs in both bulk and nanostructured forms by energy transfer channels among rare-earth ions in interstitial clusters.In this work,a comprehensive analysis of the Er^(3+):Yb^(3+):CaF_(2)crystalline structure,photoluminescence,and energy transfer from Yb^(3+)to Er^(3+)is presented for powders prepared by combustion synthesis.The Er^(3+):Yb^(3+):CaF_(2)powders display exceptional photon down-shift and up-conversion when exposed to NIR light(λ=975 nm).The luminescence spectral change of the NIR emission around 1.5μm,which corresponds to the Er^(3+)electronic transition ^(4)I_(13/2)→^(4)I_(15/2),was investigated in a temperature range of 298-423 K for application in temperature sensing of biological systems exploring the third biological window.The luminescence intensity ratio technique was applied to the thermally coupled Stark sublevels of states^(4)I_(13/2)and^(4)I_(15/2)with the highest estimated temperature relative sensitivity being around 0.4%/K at 298 K.展开更多
基金This work was supported by the National Natural Science Foundation of China(No.61432016 and No.61521092)the Key Program of the Chinese Academy of Sciences(ZDRWXH-2017-1)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC05020000).
文摘This paper presents a 1.2 V high accuracy thermal sensor analog front-end circuit with 7 probes placed around the microprocessor chip.This analog front-end consists of a BGR(bandgap reference),a DEM(dynamic element matching)control,and probes.The BGR generates the voltages linear changed with temperature,which are followed by the data read out circuits.The superior accuracy of the BGR’s output voltage is a key factor for sensors fabricated via the FinFET digital process.Here,a 4-stage folded current bias structure is proposed,to increase DC accuracy and confer immunity against FinFET process variation due to limited device length and low current bias.At the same time,DEM is also adopted,so as to filter out current branch mismatches.Having been fabricated via a 12 nm FinFET CMOS process,200 chips were tested.The measurement results demonstrate that these analog front-end circuits can work steadily below 1.2 V,and a less than 3.1%3σ-accuracy level is achieved.Temperature stability is 0.088 mV/℃across a range from-40 to 130℃.
基金supported by the National Key Research and Development Program of China(2023YFB3809800)the National Natural Science Foundation of China(52172249,52525601)+2 种基金the Chinese Academy of Sciences Talents Program(E2290701)the Jiangsu Province Talents Program(JSSCRC2023545)the Special Fund Project of Carbon Peaking Carbon Neutrality Science and Technology Innovation of Jiangsu Province(BE2022011).
文摘Flexible fiber sensors,However,traditional methods face challenges in fabricating low-cost,large-scale fiber sensors.In recent years,the thermal drawing process has rapidly advanced,offering a novel approach to flexible fiber sensors.Through the preform-tofiber manufacturing technique,a variety of fiber sensors with complex functionalities spanning from the nanoscale to kilometer scale can be automated in a short time.Examples include temperature,acoustic,mechanical,chemical,biological,optoelectronic,and multifunctional sensors,which operate on diverse sensing principles such as resistance,capacitance,piezoelectricity,triboelectricity,photoelectricity,and thermoelectricity.This review outlines the principles of the thermal drawing process and provides a detailed overview of the latest advancements in various thermally drawn fiber sensors.Finally,the future developments of thermally drawn fiber sensors are discussed.
文摘The monolithic integrated micro sensor is an important direction in the fields of integrated circuits and micro sensors. In this paper,a monolithic thermal vacuum sensor based on a micro-hotplate （MHP） and operating under constant bias voltage conditions was designed. A new monolithic integrating mode was proposed,in which the dielectric and passiva- tion layers in standard CMOS processes were used as sensor structure layers,gate polysilicon as the sacrificial layer,and the second polysilicon layer as the sensor heating resistor. Then, the fabricating processes were designed and the monolithic thermal vacuum sensor was fabricated with a 0. 6μm mixed signal CMOS process followed by sacrificial layer etching technology. The measurement results show that the fabricated monolithic vacuum sensor can measure the pressure range of 2- 10^5 Pa and the output voltage is adjustable.
基金the National Basic Research Program(973)of China(No.2009CB320206)the National Natural Science Foundation of China(No.60821062)
文摘With the characteristic size reducing as well as the power densities exponentially increasing, elevated chip temperatures are true limiters to the performance and reliability of integrated circuits. To address these thermal issues, it is essential to use a set of on-chip thermal sensors to monitor temperatures during operation.These temperature sampling results are then used by thermal management techniques to appropriately manage chip performance. In this paper, we propose a surface spline interpolation method to reconstruct the full thermal characterization of integrated circuits with non-uniform thermal sensor placements. We construct the thermal surface function using the mathematical tool of surface spline with the matrix calculation of the non-uniform sample data. Then, we take the coordinates of the points at grid locations into the surface function to get its temperature value so that we can reconstruct the full thermal signals. To evaluate the effiectiveness of our method,we develop an experiment for reconstructing full thermal status of a 16-core processor. Experimental results show that our method outperforms the inverse distance weighting method based on dynamic Voronoi diagram and spectral analysis techniques both in the average absolute error metric and the hot spot absolute error metric with short enough runtime to meet the real-time process demand. Besides, our method still has the advantages such as its mathematical simplicity with no need of pre-process.
基金the National Natural Science Foundation of China(No.61501377)
文摘Using embedded thermal sensors, dynamic thermal management(DTM) techniques measure runtime thermal behavior of high-performance microprocessors so as to prevent thermal runaway situations. The number of placed sensors should be minimized, while guaranteeing accurate tracking of hot spots and full thermal characterization. In this paper, we propose a rigid sensor allocation and placement technique for determining the minimal number of thermal sensors and the optimal locations while satisfying an expected accuracy of hot spot temperature error based on dual clustering. We analyze the false alarm rates of hot spots using the proposed methods in noise-free, with noise and sensor calibration scenarios, respectively. Experimental results confirm that our proposed methods are capable of accurately characterizing the temperatures of microprocessors.
文摘Low Resolution Thermal Array Sensors are widely used in several applications in indoor environments. In particular, one of these cheap, small and unobtrusive sensors provides a low-resolution thermal image of the environment and, unlike cameras;it is capable to detect human heat emission even in dark rooms. The obtained thermal data can be used to monitor older seniors while they are performing daily activities at home, to detect critical situations such as falls. Most of the studies in activity recognition using Thermal Array Sensors require human detection techniques to recognize humans passing in the sensor field of view. This paper aims to improve the accuracy of the algorithms used so far by considering the temperature environment variation. This method leverages an adaptive background estimation and a noise removal technique based on Kalman Filter. In order to properly validate the system, a novel installation of a single sensor has been implemented in a smart environment: the obtained results show an improvement in human detection accuracy with respect to the state of the art, especially in case of disturbed environments.
基金The Chinese Aeronautics Science Foundation(99I5 10 0 6)Foundation for University Key Teacherby the Ministry of Education
文摘According to the sensing structure of a practical silicon resonant pressure micro sensor whose preliminary sensing unit is a square silicon diaphragm and the final sensing unit is a silicon beam resonator, its operating mechanism is analyzed. The thermal resistor acts as the excited unit, and the piezoresistive unit acts as the detector, for the above micro sensor. By using the amplitude and phase conditions, the self exciting closed loop system is investigated based on the operating mechanism for the abov...
基金Project supported by the National Natural Science Foundation of China.
文摘A thermal sensor for material identification is proposed. This paper describes the model,design, and testing of the sensor. Some factors of the detector which affect the performancesof the sensor are discussed. A new concept called the thermal sense characteristic parameter isadvanced, and the relationship between the thermal sense characteristic parameter and theresponse of the sensor is given. A method for computing thermal sense characteristic param-eter from the response of the sensor is indicated. Based on our developed sensor, the correc-tion rates of the testing results of the seven materials (copper, aluminum, steel, rubber, PCB,polyflon, paper) from 130 identifications are 100%.
基金Project supported by the National Natural Science Foundation of China (Grant No 60576053)Technology Innovation of Chinese Academy of Sciences (Grant No CXJJ-176)
文摘This paper describes a micro thermal shear stress sensor with a cavity underneath, based on vacuum anodic bonding and bulk micromachined technology. A Ti/Pt alloy strip, 2μm×100μm, is deposited on the top of a thin silicon nitride diaphragm and functioned as the thermal sensor element. By using vacuum anodic bonding and bulk-si anisotropic wet etching process instead of the sacrificial-layer technique, a cavity, functioned as the adiabatic vacuum chamber, 200μm×200μm×400μm, is placed between the silicon nitride diaphragm and glass （Corning 7740）. This method totally avoid adhesion problem which is a major issue of the sacrificial-layer technique.
基金Project supported in part by the Brazilian Agency Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)。
文摘Luminescent materials for application in temperature sensing have caught a lot of interest in recent years.Particularly erbium(Er^(3+))-doped fluoride-based materials(EFM),which are readily accessible by near-infrared(NIR)excitation to produce efficient photon conversion.It has been established that ytterbium(Yb^(3+))may improve the performance of EFMs in both bulk and nanostructured forms by energy transfer channels among rare-earth ions in interstitial clusters.In this work,a comprehensive analysis of the Er^(3+):Yb^(3+):CaF_(2)crystalline structure,photoluminescence,and energy transfer from Yb^(3+)to Er^(3+)is presented for powders prepared by combustion synthesis.The Er^(3+):Yb^(3+):CaF_(2)powders display exceptional photon down-shift and up-conversion when exposed to NIR light(λ=975 nm).The luminescence spectral change of the NIR emission around 1.5μm,which corresponds to the Er^(3+)electronic transition ^(4)I_(13/2)→^(4)I_(15/2),was investigated in a temperature range of 298-423 K for application in temperature sensing of biological systems exploring the third biological window.The luminescence intensity ratio technique was applied to the thermally coupled Stark sublevels of states^(4)I_(13/2)and^(4)I_(15/2)with the highest estimated temperature relative sensitivity being around 0.4%/K at 298 K.
