A wearable Electronic Nose SoC for healthier living

The Electronic nose (E-Nose) system has the potential for personal healthcare applications but is restricted by size and cost. This study reports the world's first E-Nose system-on-chip (SoC), which fully integrates the sensor array and signal processing circuit. The E-Nose SoC has been designed and fabricated using TSMC 0.18μm 1P6M CMOS technology. The sensor array is coated with multiple-walled carbon nanotubes (MWNTs) conducting polymers. The signal processing circuit is composed of interface circuitry, analog-to-digital converter, memory, and microprocessor embedded with a pattern recognition algorithm. The power consumption of the chip was measured at 1.05mW, making it very suitable for a wearable device. The E-Nose SoC has been integrated in a prototype, and successfully recognized eight odors emulating decayed fish, liver damage, careinogen and industrial solvent.