I worked with Professor Eric Paulos at Carnegie Mellon University on this project. This is a wearable device that can measure concentration of atmospheric VOC (volatile organic compounds). These gadgets were meant for the Clean Air Initiative in Pittsburgh and funded by the Heinz foundation.
These gadgets were demonstrated by Professor Paulos at the White House Technology Office. The sensor is interfaced to a microcontroller and runs off a 9V battery. I designed the PCB and wrote the firmware for the gadet. The video below shows its function.