CMOS Biosensor IC Focusing on Dielectric Relaxations of Biological Water With 120 and 60 GHz Oscillator Arrays

In this paper, a CMOS biosensor integrated circuit (IC) focusing on dielectric relaxations of biological water with 120 and 60 GHz oscillator arrays is proposed. To realize label-free biosensing, we focus on frequencies around 100 GHz where changes in the dielectric constant of water become prominent as many a water molecule is bound to biomolecules. To detect the state of the biological water, sensing elements based on LC-oscillators operating at 120 and 60 GHz are realized using the 65 nm CMOS process. The sizes of the sensing elements are significantly smaller than the wavelengths of the operating frequencies, therefore 2-D arrays can be implemented in a chip. The trial chip enables us to obtain spatial distributions of the targets. In this paper, the cultivated bacterial colony growth is monitored and other biosensing applications are explained, which showcase possibilities for using the biosensor IC.