Electrodeposited copper inductors for intraocular pressure telemetry

A microsystem for wireless long-term measurement of the intraocular pressure is presented. The sensing element is a novel distributed parallel-resonant inductive-capacative circuit. with a pressure-dependent resonance frequency. This circuit is bared upon a twofold on-chip deposited inductor. The high Q inductor is deposited by electrodeposition of copper on a micromachined chip incorporating a pressure-sensitive diaphragm. Test structures were fabricated and characterized. Q factors of 30 at 45 MHz and inductance values of 0.4 mu H are obtained for 3 x 3 mm(2) structures.