Two-Chip Wireless H2S 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 <;4mm
³
, requires only a power source & antenna and no additional components, and has been demonstrated to acquire signals resulting from H
₂
S gas and wirelessly transmit results at 2.4GHz.