Nano Archive

Hydrogel-based microsensors for wireless chemical monitoring

Lei, Ming and Baldi, Antonio and Nuxoll, Eric and Siegel, Ronald A. and Ziaie, Babak (2009) Hydrogel-based microsensors for wireless chemical monitoring. Biomedical Microdevices, 11 (3). pp. 529-538.



We report fabrication and characterization of a new hydrogel-based microsensor for wireless chemical monitoring. The basic device structure is a high-sensitivity capacitive pressure sensor coupled to a stimuli-sensitive hydrogel that is confined between a stiff porous membrane and a thin glass diaphragm. As small molecules pass through the porous membrane, the hydrogel swells and deflects the diaphragm which is also the movable plate of the variable capacitor in an LC resonator. The resulting change in resonant frequency can be remotely detected by the phase-dip technique. Prior to hydrogel loading, the sensitivity of the pressure sensor to applied air pressure was measured to be 222kHz/kPa over the range of 41.9-51.1MHz. With a pH-sensitive hydrogel, the sensor displayed a sensitivity of 1.16MHz/pH for pH3.0-6.5, and a response time of 45 minutes.

Item Type:Article
Subjects:Engineering > Nanotechnology applications in mechanical engineering
ID Code:5111
Deposited By:CSMNT
Deposited On:25 Aug 2010 07:52
Last Modified:25 Aug 2010 07:52

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