Two-Chip Wireless H 2 S Gas Sensor System Requiring Zero Additional Electronic Components

We describe a wireless hydrogen sulfide (H 2 S) gas sensor system comprised of two integrated circuits: a chemically-sensitive field effect transistor (CS-FET) sensor and a single-chip micro-mote (SCµM). The sensor IC is a bulk transistor functionalized to respond to H 2 S. The SCµM IC uses an ARM Cortex M0 to digitize sensor voltage via an ADC and transmit data through a 2.4GHz FSK transmitter based on an ultra-small, crystal-free, free-running ring oscillator. The IC pair has combined volume 2 S gas and wirelessly transmit results at 2.4GHz.