A urine testing chip based on the complementary split-ring resonator and microfluidic channel

A urine testing chip based on the complementary split-ring resonator (CSRR) coupling with a microstrip and the microfluidic channel was developed and demonstrated for determining the water content of the urine. The CSRR is a resonant type of electromagnetic detector, which is sensitivity to the complex permittivity of materials. In addition, the complex permittivity of the tested urine sample is varied with the change of urine composition. Results show that the resonant frequency increased as the urine color became darker due to the decreased water content. Therefore, this microwave technique of the CSRR is proper to distinguish the urine for monitoring the hydration state.