We present a MEMS affinity glucose sensor using permittivity measurements. This device employs a biocompatible glucose-specific polymer as the sensing solu- tion. By introducing the polymer solution between two electrodes, the permittivity of the polymer solution can be measured from the capacitance changes induced by glu- cose binding. We characterize the frequency-dependent complex permittivity ... [Show full abstract] and the specificity of our device. This glucose sensor has potential use in implantable, stable, long-term, continuous glucose monitoring for diabetes management.