Compact Impedance Spectroscopy for High Density Sensor Arrays

Impedance Spectroscopy (IS) is a powerful technique for characterizing materials and interrogating many sensors, particularly within evolving nanotechnologies. The instrumentation to support emerging sensor applications has, however, lagged far behind the materials and sensor development. This paper presents a mixed-signal integrated circuit suitable for chip-scale implementation of IS instrumentation to support high density sensor arrays within a microsystem platform. An IS cell was implemented and fabricated in a 0.5m CMOS process and occupies 205m x 108m. Test results show that the IS system operates correctly, but is limited by noise in the integrator. An alternative integrator is also proposed to address this.