Hermetically sealed inductor-capacitor (LC) resonator for remote pressure monitoring

This paper reports an integrated inductor-capacitor (LC) resonator structur e fabricated using bulk micromachining and anodic bonding technologies. In this resonator structure, pressure change monitored by a capacitive pressur e sensor results in the change of resonance frequency. The resonance freque ncy shift is detected by inductive coupling from an external transmission c oil; therefore, pressure can be monitored remotely using the passive LC res onator. The fabricated device size measures 3 mm x 3 mm x 0.6 mm. and press ure responsivity has been estimated to be 2 MHz/mmHg. This micromachined, h ermetically sealed structure is suitable for biomedical applications such a s intraocular, cardiovascular and brain pressure monitoring.