Nanotechnology Based Cell-All Phone-Sensors for Extended Network Chemical Sensing

Today’s chemical sensing networks work effectively to cover limited and specific physical area and environments with significant cost and overhead. In order to greatly expand coverage and realize greater WMD protection for the nation, a revolutionary breakthrough that provides for a much larger and lower cost sensing distributed network is required. In order to practice this idea, US department of homeland security, HSARPA program made a call for Cell-All Ubiquitous Biological and Chemical Sensing.

NASA Ames Research Center responded to the call and won the proposal award. The work presented here is a first ever complete intelligent network chemical sensing system with 1) a compact, low-cost, low-power, high-speed nanosensor array-based detector integrated with 2) a smartphone for detection of chemical threats and transmit the sensor data via cellphone communication system to 3) a network cloud for centralizing the chemical sensing information from multiple phone-sensors from various locations.

At NASAARC, we have developed miniaturized sensing modules that can connect with an iPhone for chemical detection using carbon nanotubes (CNT) based nanostructure materials. Our devices possess high sensitivity (ppmv - ppbv), fast response (in sec), high selectivity, low power (5mW without sampling fan and 27mW with sampling fan), and very small size like a postage stamp, and they have been demonstrated for integration with an iPhone for chemical sensing of ppm concentration level of carbon monoxide, and ammonia in Windex and chlorine gas in Bleach.

The prototype-sensing module can be easily connected with an iPhone. Software has been developed to control the sensor chip for chemical detection; to collect and process sensor data, to display the chemical identification and associated concentration, and the sensor response in real time on the iPhone screen, and to transmit sensor data via 3G and/or Wi-Fi to a central location – an Internet server, to build a wider range of sensing network.

An effective cell phone-based chemical detection network will take advantage of both the standalone computing capability of modern cellular phones and the ability to aggregate sensor data over the cellular network for distributed processing or to a centralized processing location. This chemical detection network expands the coverage and realizes greater protection for the nation from hazardous chemical attack.

Note: This work is funded by DHS HSARPA Cell_All Program.