A passive humidity monitoring system for in situ remote wireless testing of micropackages
A passive humidity monitoring system for in situ remote wireless testing of micropackages
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DOI：
10.1109/84.982864
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发表时间：
2002-02-01
影响因子：
2.7
通讯作者：
Najafi, K
中科院分区：
文献类型：
--
作者：
Harpster, TJ;Hauvespre, S;Najafi, K
本文报道了一种小型无源无线湿度监测系统（HMS），用于连续远程监测微型密封包装内的湿度变化，介绍了其在确定可植入生物医学包装的气密性中的应用，并介绍了从豚鼠体内植入的包装获得的长期性能结果。该7 x 1.2 x 1.5 mm（3）系统由一个高灵敏度电容式湿度传感器组成，该传感器与一个缠绕在铁氧体基板上的混合线圈一起形成一个LC储能电路。当湿度传感器电容响应于湿度的变化而变化时，电路的谐振频率变化。HMS可分辨2 cm范围内+/-2.5%RH的湿度变化。该分辨率足以监测体外或体内试验的内部包装湿度。
This paper reports a small passive wireless humidity monitoring system (HMS) for continuous remote monitoring of humidity changes inside miniature hermetic packages, presents its application in determining hermeticity of an implantable biomedical package, and presents long-term performance results obtained from packages implanted in guinea pigs. This 7 x 1.2 x 1.5 mm(3) system consists of a high-sensitivity capacitive humidity sensor that forms an LC tank circuit together with a hybrid coil wound around a ferrite substrate. The resonant frequency of the circuit changes when the humidity sensor capacitance changes in response to changes in humidity. The HMS can resolve humidity changes of +/-2.5% RH over a 2-cm range. The resolution is sufficient enough to monitor internal package humidity for either in vitro or in vivo testing.