App gives smartphones a nose for chemicalsThe compact, low-cost, low-power, high-speed device senses chemicals in the air
By Doug Page
The smartphone now has a nose. Work at NASA's Ames Research Center, in Mountain View, Calif., has resulted in a sensor and app for the iPhone that gives chemical-sensing capabilities to the cell phone.
When the postage stamp–sized device, developed by physical scientist Jing Li, is docked to an iPhone, the phone is then able to detect low concentrations of such airborne chemicals as ammonia, methane and chlorine. The compact, low-cost, low-power, high-speed device senses chemicals in the air using a "sample jet" and a multiple-channel silicon-based sensing chip, which consists of 16 nanosensors.
"This instrument can be used for environmental monitoring of air pollutants, chemical and fuel leak detection, and homeland security and defense purposes like warfare agent detection, and at airports for explosives trace detection," Li said. Unlike the other lab chemical analysis instruments, the chemical sensor provides a small and portable tool for quick, in-situ chemical measurements, she said.
The device, funded by the Cell-All program of the Department of Homeland Security's Science and Technology Directorate, consumes a mere 5 milliwatts when idle and about 40 milliwatts when actually sniffing for chemicals. A typical iPhone 3G charger consumes about 2,000 milliwatts.
One interesting aspect of Li's early warning invention is that it gives civilians the ability to participate in their own security. Any smartphone owner can now become a pseudo-hazmat monitor during such incidents as suspected or actual gas leaks in the workplace, public venues or their own home.
"Once a gas is confirmed and identified, the information can be networked through a cell phone communication system to alert others," Li said. During accidental or deliberate release of toxic chemicals, numerous iPhone sensor readings collected by a central server could provide emergency managers with an otherwise unavailable indication of the problem's scope.
The device not only identifies the gas, but it can also determine its concentration.
The gadget was demonstrated to the press late in October at the San Diego State University Regional Technology Center.
At the moment, the device is in the proof-of-concept stage. Field testing has begun, and further research is under way to improve its data analysis capabilities.