Temperature Sensor Chip Research Articles

A new Mach–Zehnder interference temperature measuring sensor based on silica-based chip

A new type of silicon-based Mach–Zehnder interference (MZI) temperature sensor chip with “mosquito coil” structure was designed. The sensor chip used a new MZI interference structure. After the light entered the chip, it split and interfered in the combiner of the chip. The change in the surrounding temperature will cause the refractive index of the waveguide to change, which will cause the output light intensity to change. The sensor used a frequency stabilized laser that was based on a Bragg grating fiber. The experimental results showed that this structure could achieve a resolution of 0.002 °C and measuring range of 30 °C.

Real-time temperature monitoring and alarm system for biological samples storage based on FPGA

In the field of biosensing, high-quality biological samples are a prerequisite for precise analysis and detection. Strictly controlled storage temperature is crucial to ensure the stability of biological samples and achieve effective detection. Different biological samples require different temperature ranges for storage. Therefore, it is essential to design a temperature monitoring and alarm system capable of alarming based on different needs. This work presents a real-time temperature monitoring and alarm system based on the DS18B20 temperature sensor and FPGA chip. The system with simple structures has a wide temperature measurement range, an adjustable temperature alarm range, and a timely alarm function for various scenarios monitoring. This work demonstrates the temperature monitoring and alarm system for simple, accurate, and low-cost modes of temperature monitoring. The real-time temperature monitoring and alarm system will provide an effective means to strictly control the storage temperature of different biological samples, ensuring the stability and effectiveness of biological samples and the accuracy and sensitivity of biosensing and analysis.

Low Power Consumption and High Sensitivity Temperature Sensor Chip Based on Monolayer Suspended Graphene Field Effect Transistor

Low Power Consumption and High Sensitivity Temperature Sensor Chip Based on Monolayer Suspended Graphene Field Effect Transistor

A Frequency Adaptive Data Collection Method for Internet of Things Nodes

The aim of this paper is to solve the problem of a large amount of redundant data in the process of large-scale acquisition of Internet of Things sensors. This paper proposes a frequency adaptive data sensing method based on revolving gate algorithm for STM32 power safety data acquisition system. The method realizes the intelligent control of current protection terminal through three-stage current protection algorithm and frequency adaptive data acquisition algorithm. First, the three-stage current protection algorithm is used to protect the circuit, which can trip quickly in case of overload, and reduce the peak current caused by some equipment when starting up, so as to avoid damage to the equipment. Second, the arithmetic mean of each statistic is compared with the last value reported to the server. If the absolute value of the difference between the two exceeds the specified threshold range, the reported value is updated. Otherwise, it is filtered out, and the data smoothness is calculated according to the rules. The data collection interval is dynamically adjusted according to the data smoothness, which can greatly reduce the collection of redundant data and the traffic consumption of Internet of Things devices. On the server side, the inverse algorithm is used for interpolation and reconstruction to recover the collected data. This method is applied to the developed electricity safety equipment, and the electricity consumption is monitored and collected continuously for 24 h. After filtering by the frequency adaptive algorithm, only 108 pieces of data records are reported for 28,713 pieces of original data, and the compression ratio reaches 99.49[Formula: see text]. Compared with other data collection strategies, this method significantly reduces the amount of redundant data collection and the energy consumption of terminal nodes. Furthermore, this method realizes the real-time perception of line data and environmental data through current, residual current, temperature sensor and electric energy metering chip, and controls the opening and closing of wire controlled micro circuit breaker through PC817 optocoupler to protect the safety of the circuit.

MEMS-based Pt film temperature sensor chip on silicon substrate

The thin film temperature sensor chip is fabricated with the Ti/Pt film layer on a silicon substrate by micro electromechanical systems technology. Using electron beam evaporation, 10 and 100 nm thick Ti/Pt films layers are fabricated. Then, the annealing experiments for the temperature sensor chip are carried out in air and vacuum at 400 °C–800 °C. The relationship between the resistance of temperature sensor chip and tested temperature in the range of −30 °C–150 °C is studied based on different annealing conditions, and its electrical characteristic parameters are evaluated including temperature coefficient of resistance (TCR), hysteresis and measuring precision. At the same time, the morphology and grain size of the Pt film layer are studied by x-ray diffractometer, atomic force microscope and scanning electron microscope. The changes of square resistance and internal stress are tested by four probes and stress analyser to analyze the performance of the temperature sensor chip. The testing experiments show that the electrical properties of the temperature sensor chip annealed in air are better than those in vacuum. Finally, the temperature sensor chip is fabricated with the optimal performance with the annealing temperature of 800 °C for 30 min in air. Compared with before annealing, TCR increased by 75.4% from 1790 to 3140 ppm K−1, hysteresis reached 0.2% FS and precision reached 0.32% FS.

Optimization of the Intelligent Asset Management System Based on WSN and RFID Technology

With the development of Internet of Things (IoT) technology, especially the promotion of perception layer radio frequency identification (RFID) technology and wireless sensor network (WSN), a new way of thinking is provided for asset management. Applying both to the management technology of assets is an effective way to achieve intelligent asset management. This paper proposes an intelligent network applied to an asset management system based on WSN and RFID technologies. The whole intelligent asset management is divided into four layers according to the functional structure. From the top layer downward, the layers are the management and dispatch center, communication network, intelligent gateway, and data collection layer in order. Meanwhile, the functions and hardware composition of each layer are described. The data acquisition butcher is the sensing terminal of the whole intelligent asset management network. Smart nodes are its key devices to collect RFID data and sensing data to realize the intelligent sensing capability of the assets. The paper uses the MSP430 control chip, MFRC522 RF read/write chip, CC2425 wireless communication chip, temperature sensor, data memory, and voltage regulator chip to design the smart nodes in the system and details the working principle of the smart nodes and the networking process of the system. The newly designed intelligent asset management network can be deployed independently in asset management or can be integrated into the technical design of existing asset management systems. The management scheduling also collects and manages the RFID and sensing information of the area through the data collection layer, which improves the intelligent construction of the assets.

NFC Powered Implantable Temperature Sensor.

Inductively powered 99% accurate implantable temperature sensor is designed, characterized and the findings are presented in this paper. The implantable sensors deliver a continuous temperature reading to external storage or readout devices via Near Field Communication interface. A 2.76μH rectangular inductive coil printed on a thin biocompatible plastic substrate is designed to establish the coupling link through NFC interface with external readout devices. A commercially available wide range temperature sensor chip is mounted along with the developed inductive coil on the same plastic substrate. For 50 samples, the received signal strength indicator, temperature accuracy and statistical distribution of measurement levels is investigated. Comparison of predetermined temperature in a controlled temperature and humidity chamber versus the temperature reading from the developed sensors proves a 99% accuracy.

A 0.0014 mm2 150 nW CMOS Temperature Sensor with Nonlinearity Characterization and Calibration for the -60 to +40 °C Measurement Range.

This work presents a complementary metal–oxide–semiconductor (CMOS) ultra-low power temperature sensor chip for cold chain applications with temperatures down to −60 °C. The sensor chip is composed of a temperature-to-current converter to generate a current proportional to the absolute temperature (PTAT), a current controlled oscillator to convert the current to a frequency signal, and a counter as the frequency-to-digital converter. Unlike the conventional linear error calibration method, the nonlinear error of the PTAT current under the low temperature range is fully characterized based on the device model files provided by the foundry. Simulation has been performed, which clearly shows the nonlinear model is much more accurate than the linear model. A nonlinear error calibration method, which requires only two-point calibration, is then proposed. The temperature sensor chip has been designed and fabricated in a 0.13 μm CMOS process, with a total active die area of 0.0014 mm2. The sensor only draws a 140 nA current from a 1.1 V supply, with the key transistors working in the deep subthreshold region. Measurement results show that the proposed nonlinear calibration can decrease the measurement error from −0.9 to +1.1 °C for the measurement range of −60 to +40 °C, in comparison with the error of −1.8 to +5.3 °C using the conventional linear error calibration.

Architecture Characteristics and Technical Trends of UHF RFID Temperature Sensor Chip

The integration of temperature sensor (TS) and UHF RFID technology has attracted wide attention theoretically and experimentally. The architecture, power consumption, temperature measurement range, accuracy, and communication distance are key indicators of the performance of UHF RFID temperature sensor chip (RID-TSC). This work aims to provide a clearer view of the development of UHF RFID-TSC integration technology. After a systematic analysis of the characteristics of ADC, TDC, and FDC used in an integrated TS, the key low-power technologies under different architectures are summarized. Through the observation of the latest researches and commercial products, the development trend of UHF RFID-TSC technology is obtained, including on-chip and off-chip coordination, multiprotocol and multifrequency support, passive wireless sensor intelligence, miniaturization, and concealment.

Multiple USB Webcam Link Control System for Reading QR Codes of Micro PCR Biochip Calibration Factor Values

Detection systems in a range of fields including medical science, food safety, and environmental monitoring use miniaturized polymerase chain reactions that have lab-ona-chip technologies. The chip used for a micro PCR needs the correction factor of the chip temperature sensor for the exact measurement and control of temperature. The correction factor of the temperature sensor is obtained from the chip, generated as a quick response code, and attached to the chip. A universal serial bus camera connected to a PC reads the QR codes, and the data from the QR codes is used to correct the measured temperature. However, because several USB cameras cannot be operated on a single PC, users must bear the inconvenience of physically connecting USB cameras to PCs for use. In this thesis, we establish a system that automatically turns the USB cameras on and off by operating solid state relay modules and a micro controller unit used in micro PCSs. As a result, preparing micro PCRs for experiments has become more convenient and less time consuming.

A Temperature and Humidity Monitoring System of Grain Depot Based on WSN

The traditional temperature and humidity monitoring system of grain depot used to realize in wired network which needs to deploy a large number of cables. The maintainability and scalability is poor. We present a solution of monitoring temperature and humidity of grain depot based on wireless sensor network (WSN). The temperature and humidity data acquisition and control node is composed of digital temperature and humidity sensor and RF wireless chip and the main control chip. Based on the Zigbee technology, these nodes construct a WSN in Ad Hoc in order to collect, monitor and control the temperature and humidity in the monitoring area. The convergence node in the WSN will packed acquisition data from other nodes and then transmit them to a remote monitoring host through the GPRS wireless mobile network. By means of the statistical analysis of the real-time data collected, the monitoring host can alarm and feedback control the temperature and humidity of grain depot. The experimental results show that the system has strong scalability, low power consumption and high efficiency.

System-on-fluidics immunoassay device integrating wireless radio-frequency-identification sensor chips

A simple and sensitive point-of-care-test (POCT) device for chemiluminescence (CL) immunoassay was devised and tested. The device consists of a plastic flow-channel reactor and two wireless-communication sensor chips, namely, a photo-sensor chip and a temperature-sensor chip. In the flow-channel reactor, a target antigen is captured by an antibody immobilized on the inner wall of the flow-channel and detected with enzyme labeled antibody by using CL substrate. The CL signal corresponding to the amount of antigen is measured by a newly developed radio-frequency-identification (RFID) sensor, which enables batteryless operation and wireless data communication with an external reader. As for the POCT device, its usage environment, especially temperature, varies for each measurement. Hence, temperature compensation is a key issue in regard to eliminating dark-signal fluctuation, which is a major factor in deterioration of the precision of the POCT device. A two-stage temperature-compensation scheme was adopted. As for the first stage, the signals of two photodiodes, one with an open window and one with a sealed window, integrated on the photo-sensor chip are differentiated to delete the dark signal. As for the second stage, the differentiated signal fluctuation caused by a temperature variation is compensated by using the other sensor chip (equipped with a temperature sensor). The dark-level fluctuation caused by temperature was reduced from 0.24 to 0.02 pA/°C. The POCT device was evaluated as a CL immunoassay of thyroid-stimulating hormone (TSH). The flow rate of the CL reagent in the flow channel was optimized. As a result, the detection limit of the POCT device was 0.08 ng/ml (i.e., 0.4 μIU/ml).

Silicon micro thermal sensor platform at high accuracy with back side contacts

A temperature sensor platform of high accuracy and spatial resolution on a silicon substrate is presented. Spatial positioning and high precision are crucial for the thermal measurement of microdevices, where often only small temperature differences occur. This was addressed and solved by a new reusable and easy to mount temperature sensor chip. The sensor array consisted of 64 platinum thermistors arranged in a matrix of 16 rows and 4 columns. The sensors were contacted from the back side. This was realized by new techniques using KOH-etched cavities and metal membranes. Each sensor was realized with a size of 52μm×52μm, while the minimum required space per sensor in terms of integration density was 784μm×784μm. A thorough calibration and error assessment procedure resulted in a measurement accuracy of 78mK. The chip may be used for detecting spatial temperature distributions on microchips. Applications are presented for measuring water temperatures directly inside silicon microchannels and for tracking the surface temperature of a chip containing a microchannel.

Design and Realization of Hand-Held Smart Electrothermal Umbrella Applied New Materials

In this paper, a new type of hand-held smart eletrothermal umbrella has been designed and realized. Bionic lotus leaf polymer film, which is hydrophobic, is applied as umbrella fabric. Based on micro controller unit STC12C5A60S2, the system starts work with temperature sampling of outdoor environment by temperature sensor chip DS18B20, when the temperature is lower than 10°C, high current half bridge chip BTS7970 drives the carbon- nanofiber- electrothermal -heating- film to work. Also, the system is equipped with manual -heating module. A LED light of caution stands on the top of the umbrella that can flicker following a regular pattern controlled by MCU. A LED highlight is mounted at the bottom of the hand handle in order to illuminate the ground at night. Additionally, a USB interface, which can provide 5V output, is reserved to charge exterior electric device. The whole system is powered by eight 18650 lithium batteries, when fully charged, they can support the system working 8 hours constantly. With a synthesis of aesthetic, pragmatic function which can be expanded, and high performance, this new type of umbrella enjoys broad market and perspective.

An evaluation of the embedment of a Radio Frequency Integrated Circuit with a temperature detector in building envelopes for energy conservation

Concrete is the primary material for building envelopes in some parts of the world, and its ability to store heat as well as its dynamic temperature changes will not only affect the deterioration rate of the exterior wall but will also greatly influence the energy efficiency of interior air conditioning. There are many methods for measuring the inner temperature of concrete, but they often have limitations, such as indirect estimation, cable installation requirements, high cost, or heterogeneity of the sample structure. In order to measure the internal temperature of concrete, this study integrated a Radio Frequency Integrated Circuit (RFIC) with a temperature sensor chip and embedded the device in concrete structures. A Smart Temperature Information Material (STIM) was thus developed. This device overcomes the aforementioned constraints, allows direct measurement and wireless transmission, and is able to constantly monitor temperature changes from a distance. The experiment embedded STIM into 5 concrete specimens that simulated rooftop insulation (50cm×50cm×15cm) to measure the thermal performance of each insulation material, and the effect of weather conditions and the heat release/absorption rates on the thermal performance. The results of the study can be used as a reference for selecting materials for building design or maintenance and analysis of the energy efficiency of building envelopes.

A microchip integrated temperature sensor with RF communication channel and on-chip antenna

A wireless CMOS temperature sensor chip performing an embedded RF antenna is presented. The RF carrier is produced by a three-stage ring oscillator that also acts as sensing element exploiting a linear dependence of oscillation frequency on temperature. The antenna is a square loop fabricated using the top metal layer provided by the 0.35 μm CMOS technology. Oscillation frequency shifts due to bias voltage fluctuations are circumvented by using a mathematical technique.The microchip provides an RF power level of -45 dBm at a distance of 1 m. The average power consumption is about 50 μW.

A 32 × 32 temperature and tactile sensing array using PI-copper films

The development of a flexible 32 × 32 temperature and tactile sensing array, which will serve as the artificial skin for robot applications, is presented in this work. Pressure conductive rubber is employed as the tactile sensing material, and discrete temperature sensor chips are employed as the temperature sensing cells. Small disks of pressure conductive rubber are bonded on predefined interdigital copper electrode pairs which are patterned on a flexible copper–polyimide substrate which is fabricated by micromachining techniques. This approach can effectively reduce the crosstalk between each tactile sensing element. The mechanical and electrical properties of tactile sensing elements are measured. Also, the corresponding scanning circuits are designed and implemented. The temperature and tactile sensing elements are heterogeneously integrated on the flexible substrate. By using the integrated 32 × 32 sensing arrays, temperature and tactile images induced by the heaters/stamps of different shapes have been successfully measured. The flexible sensor arrays are bendable down to a 4-mm radius without any degradation in functionality.

An integrated flexible temperature and tactile sensing array using PI-copper films

This paper presents the design, fabrication and measurement of a flexible 8 × 8 temperature and tactile sensing array which will be used as the artificial skin for robot applications. The temperature and tactile sensing elements are heterogeneously integrated on a flexible copper-PI film using micromachining techniques. The tactile sensing elements are formed by dispensing conductive polymer on the pre-defined interdigital copper electrodes. This novel fabrication method can effectively reduce the crosstalk between each sensing element. The strategy and the verification for reducing crosstalk currents are described. The mechanical and electrical properties of tactile sensing elements are measured. Also, discrete temperature sensor chips are employed as the temperature-sensing cells. Scanning circuits are implemented. Finally, measured temperature and tactile images have been successfully obtained by using the integrated 8 × 8 sensing arrays. The flexible sensor arrays are bendable down to a 4-mm radius without any degradation in functionality.

CMOS microhotplate sensor system for operating temperatures up to 500 °C

A monolithic gas sensor microsystem fabricated in industrial CMOS-technology combined with post-CMOS micromachining is presented, which comprises a new type of microhotplate for operating temperatures up to 500°C and specifically designed on-chip circuitry. These high temperatures can be achieved by using carefully optimized heater geometries and layouts, micropatterned Pt-temperature sensors and Pt-electrodes as well as a post-CMOS local passivation. Moreover, the on-chip Pt-temperature sensor requires a fully differential low-noise amplifier as a consequence of its low overall resistance. A logarithmic converter for measuring the metal-oxide resistance changes upon gas exposure and a bulk chip temperature sensor were co-integrated. The monolithic system was characterized, and operating temperatures up to 500°C were achieved and controlled at ±2°C precision. The correlation between input reference voltage and microhotplate temperature was found to be linear, which is advantageous for temperature modulation. A detection limit of less than 1ppm CO (40% r.h.) was established using a nanocrystalline Pd-doped (0.2wt.%) tin-oxide thick film as sensitive material.

Low cost ceramic sensors for biomedical use: a revolution in transcutaneous blood oxygen monitoring?

A new type of integrated sensor structure has been developed for transcutaneous blood oxygen monitoring. It is based on multilayer ceramic technology which is used in the fabrication of high density electronic interconnection systems. The electrodes are made by thick film technology using precious metal pastes. The heating element is an integrated thick film resistor and a pn junction is used as temperature sensor chip. The sensor structure is based on microelectronic technologies and can be produced at low costs. The technology, parameters and results from the praxis will be demonstrated in the paper.