A MEMS viscometric glucose monitoring device

We report a MEMS device for continuously monitoring glucose levels in diabetics. The device features a micro-cantilever and a semi-permeable membrane, which are integrated with micro-channels forming a miniature device chamber with a volume of 0.4 /spl mu/l. The sensor is based on affinity binding principles using the Dextran/Con-A system. The glucose concentration is determined by detecting viscosity changes induced by binding of glucose with Con-A through measurement of the cantilever's vibration parameters. The device is capable of measuring physiologically relevant glucose concentrations from 0 to 25 mM with a resolution better than 0.02 mM. The time for the system to reach binding equilibrium is less than 5 minutes in response to changes in glucose concentration.