The device Li developed is about the size of a postage stamp and is designed to be plugged in to an iPhone to collect, process and transmit sensor data. The new device is able to detect and identify low concentrations of airborne ammonia, chlorine gas and methane. The device senses chemicals in the air using a ‘sample jet’ and a multiple-channel silicon-based sensing chip, which consists of 16 nanosensors, and sends detection data to another phone or a computer via telephone communication network or Wi-Fi.
Pictured is the chemical sensing prototype plugged into an iPhone 30-pin dock connector with the display-side up.
More info and photos in the full article here.