The paper reports the localization principle and method for the capsule in the non-invasive detecting system of gastrointestinal （GI） tract utilizing one permanent and three magnetoresistive sensors. When the capsul...The paper reports the localization principle and method for the capsule in the non-invasive detecting system of gastrointestinal （GI） tract utilizing one permanent and three magnetoresistive sensors. When the capsule is localized in practice, the permanent magnet is fixed inside the capsule, and the four magnetoresistive sensors are installed outside body. The permanent magnet＇s coordinate values can be solved by the magnetic dipole theory and optimum iterated method. The experiment shows the localization distance can reach 300mm by employing the HMC1023 magnetoresistive sensors and the NdFeB45 09 mm × 5 mm permanent magnet, and the errors of single coordinate direction and radius vector are 0 - 58 mm and 0.1-62.9 nun respectively. The localization precision is acceptable basically, and it has some possibilities improving the precision and distance in the future. Moreover, the localization system makes the localization be reality because of decreasing the number of sensors, and it economizes the capsule＇s volume because of decreasing the permanent magnet＇s dimension, too.展开更多
Magnetic sensors based on tunneling magnetoresistance(TMR)effect exhibit high sensitivity,small size,and low power consumption.They have gained a lot of attention and have potential applications in various domains.Thi...Magnetic sensors based on tunneling magnetoresistance(TMR)effect exhibit high sensitivity,small size,and low power consumption.They have gained a lot of attention and have potential applications in various domains.This study first introduces the development history and basic principles of TMR sensors.Then,a comprehensive description of TMR sensors linearization and Wheatstone bridge configuration is presented.Two key performance parameters,the field sensitivity and noise mechanisms,are considered.Finally,the emerging applications of TMR sensors are discussed.展开更多
The finding of giant magnetoresistive（GMR） effect develops a new field for the sensing application with magnetic nanoparticles（MNPs） labeling. A convenient GMR sensor was built with a permanent magnet to excite th...The finding of giant magnetoresistive（GMR） effect develops a new field for the sensing application with magnetic nanoparticles（MNPs） labeling. A convenient GMR sensor was built with a permanent magnet to excite the MNPs in this work. The sensing element contained a Wheatstone bridge with the GMR material as one of its branches. The magnetic field from MNPs unbalanced the Wheatstone bridge. After being amplified, the output signals were recorded. The construction and optimization of the magnetoresistive sensing platform were discussed in detail. The detection of three kinds of MNPs validated the performance of the proposed GMR sensor. The sensor showed a fast response to the addition or removal of MNPs. Because of its simplicity, this kind of GMR sensor can be developed in a routine laboratory. The finding of this new GMR sensor will promote the development of the method of probing biomoleeules and the study on the biomolecular interaction after being labeled magnetically.展开更多
基金National Natural Science Foundation of China(No30570485)National 863 Project of China (No2004AA404013)
文摘The paper reports the localization principle and method for the capsule in the non-invasive detecting system of gastrointestinal （GI） tract utilizing one permanent and three magnetoresistive sensors. When the capsule is localized in practice, the permanent magnet is fixed inside the capsule, and the four magnetoresistive sensors are installed outside body. The permanent magnet＇s coordinate values can be solved by the magnetic dipole theory and optimum iterated method. The experiment shows the localization distance can reach 300mm by employing the HMC1023 magnetoresistive sensors and the NdFeB45 09 mm × 5 mm permanent magnet, and the errors of single coordinate direction and radius vector are 0 - 58 mm and 0.1-62.9 nun respectively. The localization precision is acceptable basically, and it has some possibilities improving the precision and distance in the future. Moreover, the localization system makes the localization be reality because of decreasing the number of sensors, and it economizes the capsule＇s volume because of decreasing the permanent magnet＇s dimension, too.
基金financially supported by Beijing Municipal Science and Technology Project(No.Z201100004220002)the International Collaboration Project B16001+1 种基金the Key Research and Development Program of Shandong Province of China(No.2020S020201-01621)the Magnetic Sensor Innovation Platform from Laoshan District。
文摘Magnetic sensors based on tunneling magnetoresistance(TMR)effect exhibit high sensitivity,small size,and low power consumption.They have gained a lot of attention and have potential applications in various domains.This study first introduces the development history and basic principles of TMR sensors.Then,a comprehensive description of TMR sensors linearization and Wheatstone bridge configuration is presented.Two key performance parameters,the field sensitivity and noise mechanisms,are considered.Finally,the emerging applications of TMR sensors are discussed.
基金Supported by the National Basic Research Program of China（No.2011CB707703）, the National Natural Science Foundation of China（Nos.21375064, 21075068） and the Fundamental Research Funds for the Central Universities of China（No.20130031110016）.
文摘The finding of giant magnetoresistive（GMR） effect develops a new field for the sensing application with magnetic nanoparticles（MNPs） labeling. A convenient GMR sensor was built with a permanent magnet to excite the MNPs in this work. The sensing element contained a Wheatstone bridge with the GMR material as one of its branches. The magnetic field from MNPs unbalanced the Wheatstone bridge. After being amplified, the output signals were recorded. The construction and optimization of the magnetoresistive sensing platform were discussed in detail. The detection of three kinds of MNPs validated the performance of the proposed GMR sensor. The sensor showed a fast response to the addition or removal of MNPs. Because of its simplicity, this kind of GMR sensor can be developed in a routine laboratory. The finding of this new GMR sensor will promote the development of the method of probing biomoleeules and the study on the biomolecular interaction after being labeled magnetically.
