Jing Li, a scientist in California's NASA Ames Research Center, has designed a smartphone plug-in device that could sense chemicals from the environment. Current prototype of the device works with the iPhone, and plugs into the handset's bottom connector. The device can detect chemicals in ambient air such as methane, ammonia and chlorine gas. It's designed to connect to a network through WiFi or a regular phone connection in order to send alerts to other phones also equipped with the device. According to Li, a previous prototype of the device was the size of a soda can - this iteration, however, is touted as one of the smallest complete sensing-device in the world.

The device contains a silicon-based sensing chip with 64 nanosensors. Li and colleagues had to work on making a chip that can contain all those nanosensors and yet is compact, high-speed, low-power and low-cost. The chip consumes 5 milliwatts, and can last for 100 hours when ran continuously. Although connected to a bottom connector and draws power through it, data communication is routed through the audio input jack due to restrictions imposed by Apple upon third-party developers. There might be a chance that the second phase of the device's development could be made for a smartphone other than an iPhone. Whether this happens or not, Li envisions future prototypes to be used by fire fighters and other kinds of emergency responders.