A hydrogel-based implantable micromachined transponder for wireless glucose measurement
A hydrogel-based implantable micromachined transponder for wireless glucose measurement
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DOI：
10.1089/dia.2006.8.112
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发表时间：
2006-02-01
影响因子：
5.4
通讯作者：
Ziaie, Babak
中科院分区：
文献类型：
--
作者：
Lei, Ming;Baldi, Antonio;Ziaie, Babak
在本文中，我们报告了一种基于水凝胶的新型植入式无线葡萄糖传感器的设计和表征。基本设备结构是与刺激敏感水凝胶耦合的无源[电感器/电容器（LC）]微机械谐振器，该水凝胶被限制在坚硬的纳米多孔膜和薄玻璃隔膜之间。当葡萄糖分子穿过纳米多孔膜时，水凝胶膨胀并使柔性玻璃隔膜发生偏转，该玻璃隔膜是全集成无源LC谐振器中可变电容器的可移动板。可以远程检测谐振频率的相应变化。将葡萄糖敏感的苯基硼酸基水凝胶加载到微应答器中，并测量其灵敏度和时间响应。在水凝胶加载之前，在 51 --> 42 MHz 频率范围内，测量压力传感器对施加气压的灵敏度为 -222 kHz/kPa。该传感器在葡萄糖浓度范围 0-20 mM（pH 7.4）内显示出 -34.3 kHz/MM 的灵敏度，响应时间为 90 分钟。动态响应虽然在这样的值下是不可接受的，但是可以通过减小水凝胶厚度以及减小传感器和多孔膜厚度来容易地改进。应答器的整体尺寸为 5 X 5 X 0.8 mm(3)，足够小，适合皮下植入。
In this paper, we report on the design and characterization of a new hydrogel-based implantable wireless glucose sensor. The basic device structure is a passive [inductor/ capacitor (LC)] micromachined resonator coupled to a stimuli-sensitive hydrogel, which is confined between a stiff nanoporous membrane and a thin glass diaphragm. As glucose molecules pass through the nanoporous membrane, the hydrogel swells and deflects the flexible glass diaphragm, which is the movable plate of the variable capacitor in the totally integrated passive LC resonator. The corresponding change in resonant frequency can be remotely detected. A glucose-sensitive phenylboronic acid-based hydrogel was loaded into the microtransponder, and its sensitivity and time response were measured. Prior to hydrogel loading, the sensitivity of the pressure sensor to applied air pressure was measured to be -222 kHz/kPa over the frequency range 51 --> 42 MHz. The sensor showed a sensitivity of -34.3 kHz/MM over the glucose concentration range 0-20 mM (at pH 7.4), and a response time of 90 min. The dynamic response, although unacceptable at such values, can be easily improved by decreasing the hydrogel thickness and reducing the sensor and porous membrane thicknesses. The transponder's overall dimensions were 5 X 5 X 0.8 mm(3), small enough for subcutaneous implantation.