Homeland Security Backs Cell Phone Sensors to “Crowdsource” Detection of Deadly Chemicals

Bruce V. Bigelow 11/2/09

DHS officials meeting in San Diego last week say they have provided total funding of roughly $3 million over the past year for what they call their “Cell-All” program. The funding went to three different R&D groups—including two teams based in San Diego—who successfully demonstrated their prototypes Oct. 27 at San Diego State University’s Regional Technology Center for about 40 government and industry representatives. Among other things, the center serves as a technology clearinghouse and homeland security test bed for public safety agencies in the region.

While implementing such technology is still years away, DHS officials say the concept would make it possible to deploy millions of chemical sensors in the pockets, purses, and belt holsters of cell phone users throughout the United States. Their goal is to integrate miniaturized “sniffer” technology with the mobile handset’s operating system so that a sensor that detects certain volatile chemical compounds would trigger a warning alarm on the user’s phone. At the same time, data about the chemical would be transmitted to first responders and federal emergency operations centers.

“It’s almost like crowd-sourcing the chemical detection problem,” said Stephen Dennis, who is overseeing the Cell-All program for the DHS Science and Technology Directorate in Washington D.C.

Whether a cell phone owner would still be alive after his phone helped to detect, say, a nerve gas attack is another question. But the arguments cut both ways. Japanese emergency services and hospitals were heavily criticized for their slow and uncoordinated response to the 1995 gas attack in Tokyo’s subways. Doctors at many hospitals did not realize they were dealing with cases of sarin nerve gas poisoning until a professor at Shinshu University’s school of medicine recognized the symptoms from television news accounts and mobilized a team to send diagnosis and treatment information by fax. The sarin killed 12 people and sickened thousands.

If such cell phone sensor technology is eventually deployed, Dennis emphasized the system would use an “opt-in” network that would require each cell phone user to activate the sensor in their handset. “We’re very mindful of privacy issues,” Dennis said. “Even though it’s very early in development, we want to send the message that people will control whether or not they want this technology.”

It stands to reason, though, that enough people would participate so that conceivably hundreds, or even thousands, of sensor-equipped cell phones would be present at any given time in shopping malls, airports, public transit systems, and other places where people congregate.

“Instead of large stationary [sensor] systems, you’d have numerous, ubiquitous sensors throughout a region,” Dennis said. “Putting the sensors where people are is a big goal.”

development would have to be capable of detecting the presence of chemical compounds found in explosives as well as certain deadly airborne chemicals, regardless of whether the cause is a hazardous chemical spill or terrorist attack.

The R&D teams selected for funding were culled from roughly 100 proposals that were submitted more than a year ago in response to a DHS “request for proposals” in what Dennis called a highly competitive process. All of the groups selected are based in California, and Dennis said the fact that two of the selected groups are based in San Diego was “a matter of chance, but it’s turning out to be convenient. They also talk to each other, which helps.”

The groups participating in the program, and the technologies they are developing, are:

—Engineers from Qualcomm’s (NASDAQ QCOM) government technologies unit demonstrated a cell phone that incorporates a microchip developed by privately held Seacoast Science of Carlsbad, CA, that is equipped with 10 “chemical capacitors.” The company’s technology uses microelectromechanical systems (MEMS) in which a series of chemically-sensitive polymers are used to coat a sensor platform, which acts like a sponge to absorb chemicals from the atmosphere. When a polymer absorbs a chemical, it changes that polymer’s ability to conduct electricity, which can be precisely measured and compared to a known class of chemicals.

—Rhevision Technology, a three-year-old San Diego-based startup, is developing advanced optical technology that Rhevision founder Yu-Hwa Lo invented in his optics laboratory at UC San Diego. Their concept is to combine Rhevision’s optics with a “porous silicon artificial nose” developed in the laboratory of UC San Diego Professor Michael Sailor. The millimeter-sized sensors are based on “nanophase semiconductors” developed by Sailor’s group, which are composed of nanoparticles that change color in the presence of certain molecules. Rhevision demonstrated how it has integrated its bio-inspired liquid lens technology with a cell phone camera systems to basically turn a cell phone camera into an extremely high-resolution wireless microscope. Rhevision uses its system to precisely inspect and measure color changes in the chemical sensor and compare the results with known toxic compounds.

—[Updates to clarify size of device] A team of scientists from the Center for Nanotechnology at NASA Ames Research Center outside Mountain View, CA, demonstrated a “three-in-one” nanosensor system that includes a sampling jet, sensor chip, and electronics for data acquisition on a 20-millimeter by 20-millimeter device. Multiple nanotube sensors on the chip measure changes in the electrical conductivity across the nanotube openings, and are sensitive enough to tell the difference between chlorine, ammonia, and methane. Principal investigator Jing Li says two nanosensors based on the same technology and developed by her team were part of an instrument package delivered to the International Space Station last year. The sensors are used to monitor air quality aboard the space station.

Dennis said the demonstration was intended to serve as a “proof of concept” before moving to the next step of technology development. “There were some very expensive paths we were looking to avoid—some very expensive miniaturization of components—and we wanted to first prove the function.” Following what Dennis described as “a fairly solid demonstration of the concept,” he said, “What we’re looking for now is field data. We want to see if these detection results in the laboratory can be duplicated in the field.”