A new business card size very low cost wireless electrochemical sensor device for use with smartphones and connection to the IoT has been developed. The gas sensor platform uses amperometric gas sensors, AGS, herein demonstrated for CO but easily expanded to many other important airborne contaminants. The NFC based communication could revolutionize low cost personal monitoring of environmental air quality. The technology is based on a 2-electrode electrochemical gas sensor, and can be adapted to a 3-electrode configuration as well. The platform is adaptable to other electrochemically active gases including but not limited to formaldehyde, H₂, H2S, alcohol, NO₂, CL₂, O₃ or SO₂.

The application enables NFC equipped mobile phones and devices to communicate wirelessly with the sensor on demand. The phone app NFC provides all the power necessary to read the signal from the sensor and communicate the data to the smartphone. In this configuration the sensor needs no warm-up or stabilization time and has no need for a battery or power supply. By tailoring the electro-chemistry of the sensor, a zero external bias can be used and still maintain an effective response to the target analyte. For instance, testing has been performed using composite printed Pt electrodes and an aqueous electrolyte, packaged in a small cell (roughly 15mm x 15mm x 3.8mm). Properties such as stability and linearity have been studied and will yield a device with years of service in indoor, outdoor and workplace environments. A lower detection limit of about 200 ppb CO has been achieved making ambient air quality monitoring possible as well as CO alarms. We envision that this platform will be useful for many types of AGSs with differing electrode and electrolyte configurations for other gases.

The sensor module’s electronics consist of a few passive components, an NFC communications chip with analog or digital inputs, and a low power instrumentation amplifier. With modern flexible electronics, and engineered antennae, the device can be reduced in size for embedding into just about anything. Including a printed battery enables the device to log in real time, and allows for a 3 electrode sensor configuration in a postage stamp size.

Combining techniques such as screen printing of electrodes and electronics, reel to reel manufacturing, and conformal packaging, the cost to produce a complete gas detector can be less than a dollar each! This new capability allows widespread use in studies from environmental air quality to personal health and asset protection.