SiC RF Sensor for Continuous Glucose Monitoring

It has been shown that changes in blood glucose can be sensed with an RF antenna made from silicon carbide (SiC) operating at 10 GHz. Therefore a SiC antenna patch could operate as an active sensor or as a passive sensor at 5.8 GHz for a continuous glucose monitoring system. The properties of SiC make this material ideal for biomedical applications and devices as it is not only biocompatible but also has great sensing capability. The permittivity and conductivity of the blood is glucose dependent. Thus implanting the antenna in the fatty tissue facing the muscle and blood results should result in a shift of the resonant frequency of the antenna with glucose levels. In the active sensor approach, a power supply and internal in-vivo circuitry with protection would be required. In the passive sensor approach, external circuitry sends a signal to the implanted antenna and is received back again, detecting any signal variations. Simulations in HFSS™ show that that an implanted sensor placed 2 mm from the muscle in fatty tissue would experience an approximate shift in resonant frequency of 12.3 MHz for a blood glucose change of 500 mg/dl.