Shannon Spanhake and air pollution monitor

Shannon Spanhake, a postdoctoral researcher at the University of California at San Diego's Institute for Telecommunications and Information Technology, has a pet project. She built a device that monitors air pollution. She showed off the $125 device at the Make Fest on Wednesday night.

The device includes surprisingly few parts--a Bluetooth chip, a sensing chip and an MCU, or battery pack. Installed in a cell phone, the sensor can detect levels of carbon monoxide in a given space; that data is sent via Bluetooth to a server. In the case of the Make Fest, which was being held at the Grand Hyatt hotel in San Diego, the levels in the room showed the number 11 (that's 11 parts per million). That was a good sign, given that the Environmental Protection Agency has a threshold of 32 to 35 parts per million of carbon monoxide in the air.