A hydrogel-based MEMS dielectric affinity glucose sensor

We present a hydrogel-based MEMS affinity sensor. The hydrogel is surface-immobilized, and recognizes glucose molecules via specific affinity binding. Measurement of the capacitance between a pair of electrodes sandwiching the hydrogel allows determination of glucose binding-induced change in the hydrogel's permittivity, and hence the glucose concentration. This hydrogel-based sensor design simplifies the device construction, and eliminates mechanical moving parts as well as semi-permeable membranes that are commonly used in existing devices. Our experimental results demonstrate that this sensor holds promise for use in continuous glucose monitoring in diabetes care.