柔性电导率芯片设计与营养液监测试验研究  

Design and Hydroponic Monitoring of Flexible Electroconductivity Chip

作　　者：张淼[1,2] 王丽茹 李浩榛 路逍 汪瑾 刘刚[1,2] ZHANG Miao;WANG Liru;LI Haozhen;LU Xiao;WANG Jin;LIU Gang(Key Laboratory of Smart Agriculture Systems,Ministry of Education,China Agricultural University,Beijing 100083,China;Key Laboratory of Agricultural Information Acquisition Technology,Ministry of Agriculture and Rural Affairs,China Agricultural University,Beijing 100083,China)

机构地区：[1]中国农业大学智慧农业系统集成研究教育部重点实验室,北京100083 [2]中国农业大学农业农村部农业信息获取技术重点实验室,北京100083

出　　处：《农业机械学报》2023年第4期386-393,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：浙江省重点研发计划项目(2020C02017);云南省院士工作站项目(2015IC16);中央高校基本科研业务费专项资金项目(2022TC161)。

摘　　要：设计并制备了一种基于喷墨打印的纳米银/单壁碳纳米管柔性电导率传感芯片。通过交流阻抗法对传感芯片进行建模标定,系统测试了该传感芯片的响应时间、稳定性、重复性、弯折及封装影响等性能,并与商用EC电极进行了性能对比,验证了该柔性芯片在无土栽培生菜营养液EC在线监测中的可行性。试验结果表明,叉指柔性EC芯片的电导率测定范围为25.8~3098μS/cm,标准电导率溶液的测定相对误差小于8.02%,芯片响应时间为10 s,12 h测定数据漂移小于3.91μS/(cm·h),稳定性和重复性与商用EC电极相当,0°~90°范围内弯折、PDMS封装对其性能无影响。水培生菜EC监测中,柔性EC传感芯片可准确获取营养液EC波动,检测结果与商用EC电极的最大绝对误差小于46μS/cm,最大相对误差小于3.2%,两种传感器测量结果均方根误差为28.29μS/cm。自制柔性电导率传感芯片与商用EC电极的性能相近,具有微小且可弯折等独特农业应用优势。In view of the existing problems in the detection of agricultural conductivity,such as complex detection methods,large instrument volume and high requirements for internal components,and in order to improve the detection efficiency and reduce the size of the sensor,a single⁃walled carbon nanotube flexible conductivity sensor chip based on ink⁃jet printing was designed and fabricated.The sensor chip was modeled and calibrated by AC impedance spectroscopy.The response time,stability,repeatability,bending and packaging effect of the sensor chip were systematically tested,and the error between the flexible sensor chip and the commercial EC electrode was determined.The feasibility of applying the flexible chip to the on⁃line monitoring of EC of soilless lettuce nutrient solution was verified.The experimental results showed that the total chip area was about 30 mm×40 mm,realizing miniaturization of detection.The conductivity range of modeling and calibration was 25.8~3098μS/cm,and the measurement impedance range was 160~15000Ω.There was an obvious power function relationship between the standard conductivity value and the measured impedance value,and the correlation coefficient was 0.99.The absolute error range of the verification test was-99.76~115.62μS/cm,and the relative error range was-5.89%~8.02%(FS).The measurement results of the flexible chip were in good agreement with the EC standard value.The maximum response time of the flexible EC sensor chip was 10 s.The stability fluctuation within 12 h was 3.91μS/(cm·h),and the absolute error range of five repeated measurements was-74~62μS/cm.The stability and repeatability were in good agreement with commercial EC electrodes.Bending in the range of 0°~90°and PDMS packaging had no effect on its performance.In the monitoring of EC value of hydroponic lettuce for 10 consecutive days,the maximum deviation between the flexible EC sensor chip and the commercial EC sensor was 46μS/cm.The flexible chip showed good consistency with the commercial electrode,and it

关 键 词：无土栽培 电导率检测 柔性芯片 单壁碳纳米管 

分 类 号：S151.95[农业科学—土壤学] S126[农业科学—农业基础科学]