| This thesis presents the design and characterization of an absolute capacitive pressure sensor and integrated inductor that form the basis of a hydrogel-based implantable wireless glucose sensor. In the final version of the device, a glucose-sensitive hydrogel will be constrained between the pressure sensor membrane and a rigid, permeable membrane of nanoporous alumina. As glucose diffuses across the rigid membrane, the hydrogel swells, causing the pressure sensor membrane to deflect, altering the resonant frequency of the LC circuit created by the pressure sensor and inductor. Several new analytical equations are presented for designing the pressure sensor, which are demonstrated to be in close agreement with detailed finite element simulations, and a general design methodology for absolute capacitive pressure sensors based around these equations is presented. The design and simulation of the inductor is also discussed, along with a combined analysis of the resonator's theoretical performance. |
