Hydrogel-based microsensors for wireless chemical monitoring

Author

• Ming Lei, Univ Minnesota, Dept Elect & Comp Engn
• Antonio Baldi, Univ Minnesota, Dept Elect & Comp Engn
• Eric Nuxoll, Univ Minnesota, Dept Pharmaceut
• Ronald A. Siegel, Univ Minnesota, Dept Biomed Engn
• Babak Ziaie, Birck Nanotechnology Center, Purdue UniversityFollow

Abstract

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.

Comments

Published online: 12 March 2008

Keywords

Wireless sensor; Hydrogel; Pressure sensor; Chemical sensor; Smart material

Date of this Version

6-1-2009

Recommended Citation

Lei, Ming; Baldi, Antonio; Nuxoll, Eric; Siegel, Ronald A.; and Ziaie, Babak, "Hydrogel-based microsensors for wireless chemical monitoring" (2009). Birck and NCN Publications. Paper 353.
https://docs.lib.purdue.edu/nanopub/353