▎ 摘　　要

A dual-band tunable metamaterial unit cell is presented as a refractive index sensor. Two resonance peaks at 13.41 and 16.36 THz have been achieved with almost unity absorption peaks. The unit cell has a simple structure consisting of three graphene bowties separated from a bottom gold layer by a SiO2 substrate. The structure results in sensitivity values of 3.56 and 4.76 THz/RIU whereas figure of merits of 20.30 and 24.74 RIU-1 are obtained considering the first and second operational modes, respectively. The presented sensor has a great potential for various medical diagnosis and biomedical applications.