Technology-assisted ball training systems have become a research hotspot due to their ability to provide quantitative data for guiding athletes to address their areas of improvement.However,traditional tennis training...Technology-assisted ball training systems have become a research hotspot due to their ability to provide quantitative data for guiding athletes to address their areas of improvement.However,traditional tennis training systems still have some limitations;for instance,they are subjective,expensive,heavy,and time-consuming.In this research,an assistant training tennis racket,which consists of arrayed flexible sensors and an inertial measurement unit,has been proposed to comprehensively analyze the representative actions’force and acceleration.Consisting of MXene as the sensitive material and melamine sponge as the substrate(named MMSS),the flexible sensor exhibited an excellent sensitivity of 5.35 kPa^(-1)(1.1-22.2 kPa)due to the formation of a 3D conductive network.Moreover,the sensor retained a high sensitivity of 0.6 k Pa-1in an ultrawide measurement range(22.2-266 kPa).In addition to recognizing the type of hitting action,an artificial intelligence algorithm was introduced to accurately differentiate the five typical motion behaviors with an accuracy rate of 98.2%.This study not only proposes a comprehensive assistant training tennis racket for improving the techniques of tennis enthusiasts but also a new information processing scheme for intelligent sensing and distinction of different movements,which can offer significant application potential in sports big data collection and the Internet of things.展开更多
Tactile sensors are essential components of wearable electronic devices,but there are still various problems in terms of energy supply,flexibility and skin adaptability.In this paper,we report a self-powered flexible ...Tactile sensors are essential components of wearable electronic devices,but there are still various problems in terms of energy supply,flexibility and skin adaptability.In this paper,we report a self-powered flexible tactile sensor(FTS)mainly composed of a BaTiO_(3)/polyacrylonitrile/Ecoflex(BTO/PAN/Ecoflex)composite film,which can be used for dynamically monitoring human plantar pressure,posture and other physiological and motion parameters.Combining the synergistic piezoelectric properties of PAN and BTO,the output voltage/current of the BTO/PAN/Ecoflex composite film is 4.5/5.8 times that of the BTO/Ecoflex composite film,with maximum instantaneous power that can reach up to 3.375μW.Under the action of external pressure stress,the FTS can reach a normalized voltage sensitivity and voltage linearity of 0.54 V/N and 0.98,respectively.Furthermore,a human-machine interaction test system is built,which can display the stress changes of human body monitoring parts in real time according to voltage changes and different color assignments.The developed human-machine interaction test system provides a new idea for the diagnosis of flatfoot and other medical diseases.Hence,this work proposes new FTSs that use a BTO/PAN/Ecoflex composite film with high sensitivity and great output performance,thus exhibiting immense potential application prospects in medical research,personalized recognition and human-machine interaction.展开更多
文摘射频电路优化设计是保证射频通信系统高可靠、低功耗、远距离数据传输的重要手段。针对商用CC1101射频电路传输距离短和丢包率高的问题,通过高频电磁仿真软件ADS(Advanced Design System)对CC1101射频电路中阻抗变换器、滤波器和射频全链路进行仿真优化,根据仿真结果调整元器件,并测试了改版CC1101射频电路的传输距离和数据包接收率。结果表明,优化后射频电路阻抗(115+j42Ω)更接近目标差分阻抗(116+j41Ω),回波损耗提高11 d B,插入损耗减少0.6 d B,稳定传输距离提升30 m,在传输距离为60 m时数据接收率提高33.6%。
基金supported by the National Key R&D Program of China(Grant No.2019YFE0120300)the National Natural Science Foundation of China(Grant Nos.62171414,52175554,52205608,62001431)+1 种基金the Fundamental Research Program of Shanxi Province(Grant Nos.20210302123059,20210302124610)Program for the Innovative Talents of Higher Education Institutions of Shanxi。
文摘Technology-assisted ball training systems have become a research hotspot due to their ability to provide quantitative data for guiding athletes to address their areas of improvement.However,traditional tennis training systems still have some limitations;for instance,they are subjective,expensive,heavy,and time-consuming.In this research,an assistant training tennis racket,which consists of arrayed flexible sensors and an inertial measurement unit,has been proposed to comprehensively analyze the representative actions’force and acceleration.Consisting of MXene as the sensitive material and melamine sponge as the substrate(named MMSS),the flexible sensor exhibited an excellent sensitivity of 5.35 kPa^(-1)(1.1-22.2 kPa)due to the formation of a 3D conductive network.Moreover,the sensor retained a high sensitivity of 0.6 k Pa-1in an ultrawide measurement range(22.2-266 kPa).In addition to recognizing the type of hitting action,an artificial intelligence algorithm was introduced to accurately differentiate the five typical motion behaviors with an accuracy rate of 98.2%.This study not only proposes a comprehensive assistant training tennis racket for improving the techniques of tennis enthusiasts but also a new information processing scheme for intelligent sensing and distinction of different movements,which can offer significant application potential in sports big data collection and the Internet of things.
基金supported by the National Key R&D Program of China(Grant Nos. 2019YFF0301802, 2019YFB2004802 and 2018YFF0300605)the National Natural Science Foundation of China (Grant Nos. 62101513,52175554, 51975542)+1 种基金the Applied Fundamental Research Program of Shanxi Province (Grant Nos. 201901D111146, 20210302124170)Shanxi “1331 Project” Key Subject Construction (Grant No. 1331KSC)
文摘Tactile sensors are essential components of wearable electronic devices,but there are still various problems in terms of energy supply,flexibility and skin adaptability.In this paper,we report a self-powered flexible tactile sensor(FTS)mainly composed of a BaTiO_(3)/polyacrylonitrile/Ecoflex(BTO/PAN/Ecoflex)composite film,which can be used for dynamically monitoring human plantar pressure,posture and other physiological and motion parameters.Combining the synergistic piezoelectric properties of PAN and BTO,the output voltage/current of the BTO/PAN/Ecoflex composite film is 4.5/5.8 times that of the BTO/Ecoflex composite film,with maximum instantaneous power that can reach up to 3.375μW.Under the action of external pressure stress,the FTS can reach a normalized voltage sensitivity and voltage linearity of 0.54 V/N and 0.98,respectively.Furthermore,a human-machine interaction test system is built,which can display the stress changes of human body monitoring parts in real time according to voltage changes and different color assignments.The developed human-machine interaction test system provides a new idea for the diagnosis of flatfoot and other medical diseases.Hence,this work proposes new FTSs that use a BTO/PAN/Ecoflex composite film with high sensitivity and great output performance,thus exhibiting immense potential application prospects in medical research,personalized recognition and human-machine interaction.
