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The MAIN Shirt: A Textile-Integrated Magnetic Induction Sensor Array  [PDF]
Daniel Teichmann,Andreas Kuhn,Steffen Leonhardt,Marian Walter
Sensors , 2014, DOI: 10.3390/s140101039
Abstract: A system is presented for long-term monitoring of respiration and pulse. It comprises four non-contact sensors based on magnetic eddy current induction that are textile-integrated into a shirt. The sensors are technically characterized by laboratory experiments that investigate the sensitivity and measuring depth, as well as the mutual interaction between adjacent pairs of sensors. The ability of the device to monitor respiration and pulse is demonstrated by measurements in healthy volunteers. The proposed system (called the MAIN (magnetic induction) Shirt) does not need electrodes or any other skin contact. It is wearable, unobtrusive and can easily be integrated into an individual’s daily routine. Therefore, the system appears to be a suitable option for long-term monitoring in a domestic environment or any other unsupervised telemonitoring scenario.
An Integrated ISFET pH Microsensor on a CMOS Standard Process  [PDF]
Francisco López-Huerta, Rosa María Woo-Garcia, Miguel Lara-Castro, Johan Jair Estrada-López, Agustín Leobardo Herrera-May
Journal of Sensor Technology (JST) , 2013, DOI: 10.4236/jst.2013.33010
Abstract: We present the design and integration of a nine-pH microsensor array on a single silicon substrate with its own signal readout circuit, integrated in a 0.6-μm commercial standard complementary metal oxide semiconductor (CMOS) process. An ion sensitive field effect transistor (ISFET) has been used as pH microsensor and an instrumentation amplifier as the read-out circuit. The ISFET structure is conformed by the channel length and ratio of MOS transistor, gate extended and the selective membrane, for which silicon nitride (Si3N4) is employed as an ion selective element. The complete design includes shielding around the pH microsensor and the readout circuit to avoid leakage of current to the substrate. The readout circuit is composed by three operational amplifiers and resistances that form the instrumentation amplifier, with a ±2.5 V bias has a 50 dB gain, power supply rejection ratio (PSSR) of 120 dB and common mode rejection ratio (CMRR) of 127 dB. The complete system is integrated in a 1.12 mm2 silicon area; it presents a 59 mV/pH linearity, within a concentration range of 2 to 12 of pH level, making it a good alternative for biological or medical applications.
A CMOS Integrated CC-ISFET Device for Water Quality Monitoring
Pawan Whig,Syed Naseem Ahmad
International Journal of Computer Science Issues , 2012,
Abstract: This study presents a performance analysis of low power CMOS Integrated Current Conveyor Ion Sensitive Field Effect transistor (CC-ISFET). The studys main focus is on simulation of power and performance analysis of ISFET device, which is used for water quality monitoring. This approach can improve calibration of device to a fairly wide range without the use of a high speed digital processor. The conventional devices generally used, consume high power and are not stable with temperature and frequency variations for long term monitoring. The conventional device [1] has a drawback of low value of slew rate, high power consumption, and non linear characteristics but in this novel design, the device exhibits a better slew rate, piece-wise linear characteristics, and seen consuming low power of the order of 5.7W. The functionality of the circuit is tested using Tanner simulator version 15 for a 70nm CMOS process model. Very high speed integrated circuit Hardware description language (VHDL) code for the same scheme is simulated on Xilinx ISE 10.1 and various simulation results are obtained. The proposed circuit reduces total power consumption per cycle, increases speed of operation, fairly linear and is simple to implement.This device has a simple architecture, and hence is very suitable for water quality monitoring applications.
A Miniature Integrated Multimodal Sensor for Measuring pH, EC and Temperature for Precision Agriculture  [PDF]
Masato Futagawa,Taichi Iwasaki,Hiroaki Murata,Makoto Ishida,Kazuaki Sawada
Sensors , 2012, DOI: 10.3390/s120608338
Abstract: Making several simultaneous measurements with different kinds of sensors at the same location in a solution is difficult because of crosstalk between the sensors. In addition, because the conditions at different locations in plant beds differ, in situ measurements in agriculture need to be done in small localized areas. We have fabricated a multimodal sensor on a small Si chip in which a pH sensor was integrated with electrical conductivity (EC) and temperature sensors. An ISFET with a Si3N4 membrane was used for the pH sensor. For the EC sensor, the electrical conductivity between platinum electrodes was measured, and the temperature sensor was a p-n junction diode. These are some of the most important measurements required for controlling the conditions in plant beds. The multimodal sensor can be inserted into a plant bed for in situ monitoring. To confirm the absence of crosstalk between the sensors, we made simultaneous measurements of pH, EC, and temperature of a pH buffer solution in a plant bed. When the solution was diluted with hot or cold water, the real time measurements showed changes to the EC and temperature, but no change in pH. We also demonstrated that our sensor was capable of simultaneous in situ measurements in rock wool without being affected by crosstalk.
Miniature Sensor Node with Conformal Phased Array
G. A. E. Vandenbosch,A. Vasylchenko,M. Fernandez-Bolanos,S. Brebels
Radioengineering , 2011,
Abstract: This paper reports on the design and fabrication of a fully integrated antenna beam steering concept for wireless sensor nodes. The conformal array circumcises four cube faces with a silicon core mounted on each face. Every silicon core represents a 2 by 1 antenna array with an antenna element consisting of a dipole antenna, a balun, and a distributed MEMS phase shifter. All these components are based on a single wafer process and designed to work at 17.2 GHz. Simulations of the entire system and first results of individual devices are reported.
An Electronic-Nose Sensor Node Based on a Polymer-Coated Surface Acoustic Wave Array for Wireless Sensor Network Applications  [PDF]
Kea-Tiong Tang,Cheng-Han Li,Shih-Wen Chiu
Sensors , 2011, DOI: 10.3390/s110504609
Abstract: This study developed an electronic-nose sensor node based on a polymer-coated surface acoustic wave (SAW) sensor array. The sensor node comprised an SAW sensor array, a frequency readout circuit, and an Octopus II wireless module. The sensor array was fabricated on a large K2 128° YX LiNbO3 sensing substrate. On the surface of this substrate, an interdigital transducer (IDT) was produced with a Cr/Au film as its metallic structure. A mixed-mode frequency readout application specific integrated circuit (ASIC) was fabricated using a TSMC 0.18 μm process. The ASIC output was connected to a wireless module to transmit sensor data to a base station for data storage and analysis. This sensor node is applicable for wireless sensor network (WSN) applications.
Visible Genotype Sensor Array  [PDF]
Yuichi Michikawa,Tomo Suga,Yoshimi Ohtsuka,Izumi Matsumoto,Atsuko Ishikawa,Kenichi Ishikawa,Mayumi Iwakawa,Takashi Imai
Sensors , 2008, DOI: 10.3390/s8042722
Abstract: A visible sensor array system for simultaneous multiple SNP genotyping has been developed using a new plastic base with specific surface chemistry. Discrimination of SNP alleles is carried out by an allele-specific extension reaction using immobilized oligonucleotide primers. The 3’-ends of oligonucleotide primers are modified with a locked nucleic acid to enhance their efficiency in allelic discrimination. Biotin-dUTPs included in the reaction mixture are selectively incorporated into extending primer sequences and are utilized as tags for alkaline phosphatase-mediated precipitation of colored chemical substrates onto the surface of the plastic base. The visible precipitates allow immediate inspection of typing results by the naked eye and easy recording by a digital camera equipped on a commercial mobile phone. Up to four individuals can be analyzed on a single sensor array and multiple sensor arrays can be handled in a single operation. All of the reactions can be performed within one hour using conventional laboratory instruments. This visible genotype sensor array is suitable for “focused genomics” that follows “comprehensive genomics”.
Visible Genotype Sensor Array
Yuichi Michikawa,Tomo Suga,Yoshimi Ohtsuka,Izumi Matsumoto
Sensors , 2008,
Abstract: A visible sensor array system for simultaneous multiple SNP genotyping has been developed using a new plastic base with specific surface chemistry. Discrimination of SNP alleles is carried out by an allele-specific extension reaction using immobilized oligonucleotide primers. The 3 ¢ € -ends of oligonucleotide primers are modified with a locked nucleic acid to enhance their efficiency in allelic discrimination. Biotin-dUTPs included in the reaction mixture are selectively incorporated into extending primer sequences and are utilized as tags for alkaline phosphatase-mediated precipitation of colored chemical substrates onto the surface of the plastic base. The visible precipitates allow immediate inspection of typing results by the naked eye and easy recording by a digital camera equipped on a commercial mobile phone. Up to four individuals can be analyzed on a single sensor array and multiple sensor arrays can be handled in a single operation. All of the reactions can be performed within one hour using conventional laboratory instruments. This visible genotype sensor array is suitable for ¢ € focused genomics ¢ € that follows ¢ € comprehensive genomics ¢ € .
An Integrated MEMS Gyroscope Array with Higher Accuracy Output  [PDF]
Honglong Chang,Liang Xue,Wei Qin,Guangmin Yuan,Weizheng Yuan
Sensors , 2008, DOI: 10.3390/s8042886
Abstract: In this paper, an integrated MEMS gyroscope array method composed of two levels of optimal filtering was designed to improve the accuracy of gyroscopes. In the firstlevel filtering, several identical gyroscopes were combined through Kalman filtering into a single effective device, whose performance could surpass that of any individual sensor. The key of the performance improving lies in the optimal estimation of the random noise sources such as rate random walk and angular random walk for compensating the measurement values. Especially, the cross correlation between the noises from different gyroscopes of the same type was used to establish the system noise covariance matrix and the measurement noise covariance matrix for Kalman filtering to improve the performance further. Secondly, an integrated Kalman filter with six states was designed to further improve the accuracy with the aid of external sensors such as magnetometers and accelerometers in attitude determination. Experiments showed that three gyroscopes with a bias drift of 35 degree per hour could be combined into a virtual gyroscope with a drift of 1.07 degree per hour through the first-level filter, and the bias drift was reduced to 0.53 degree per hour after the second-level filtering. It proved that the proposed integrated MEMS gyroscope array is capable of improving the accuracy of the MEMS gyroscopes, which provides the possibility of using these low cost MEMS sensors in high-accuracy application areas.
An Integrated MEMS Gyroscope Array with Higher Accuracy Output
Honglong Chang,Liang Xue,Wei Qin,Guangmin Yuan
Sensors , 2008,
Abstract: In this paper, an integrated MEMS gyroscope array method composed of two levels of optimal filtering was designed to improve the accuracy of gyroscopes. In the firstlevel filtering, several identical gyroscopes were combined through Kalman filtering into a single effective device, whose performance could surpass that of any individual sensor. The key of the performance improving lies in the optimal estimation of the random noise sources such as rate random walk and angular random walk for compensating the measurement values. Especially, the cross correlation between the noises from different gyroscopes of the same type was used to establish the system noise covariance matrix and the measurement noise covariance matrix for Kalman filtering to improve the performance further. Secondly, an integrated Kalman filter with six states was designed to further improve the accuracy with the aid of external sensors such as magnetometers and accelerometers in attitude determination. Experiments showed that three gyroscopes with a bias drift of 35 degree per hour could be combined into a virtual gyroscope with a drift of 1.07 degree per hour through the first-level filter, and the bias drift was reduced to 0.53 degree per hour after the second-level filtering. It proved that the proposed integrated MEMS gyroscope array is capable of improving the accuracy of the MEMS gyroscopes, which provides the possibility of using these low cost MEMS sensors in high-accuracy application areas.
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