We are frequently reminded how vulnerable our health and safety are to threats from nature or to those who wish to harm us.
The new sensors developed by Professor Otto Gregory of the College of Engineering at the University of Rhode Island and chemical engineering doctoral student Peter Ricci are so powerful that they can detect threats at the molecular level, they are acts of explosive materials, particles from a potentially deadly virus or illegal drugs entering the country.
“This is potentially life-saving technology,” said Gregory. “We’ve detected things at the part per quadrillion level. It’s really single molecule detection.”
Because Gregory’s sensors are so small and so powerful, there is a wide range of applications.
“The platform is wide, so you can apply it to a lot of different sites, with a lot of different end users,” Gregory said.
While his research is largely funded by the Department of Homeland Security, other government agencies have taken note of Gregory’s sensors.
The Department of Defense may be interested in using it to monitor soldiers’ injuries and detect roadside improvised explosive devices (IEDs).
If a soldier or first responder suffered an open wound caused by shrapnel, Gregory’s sensors could help determine if the wound was infected.
“Hydrogen peroxide generated by the human body for wounds is an indication of the quality or poor effectiveness of antibiotics in combating the wound,” said Ricci. “Our sensor could be used as a portable device to sniff peroxide coming from the wound at the parts per billion level.”
In Miami Heat basketball games, dogs have been used to sniff traces of COVID-19 coming from people’s skin pores. In an article published in the prestigious journal Nature, Gregory said his sensors could be used for the same purpose.
“Where dogs detect it from the skin, our sensors detect it from biomarkers in people’s breathing,” said Ricci, from West Warwick.
The Coast Guard has expressed interest in using this technology to “sniff” illicit drugs smuggled into the United States on board ships.
Shrink the “ digital dog nose ”
“Anything that can usually be sniffed by a dog, we can do it,” said Gregory. “That’s why we called it Digital Dog Nose.”
The Digital Dog Nose was featured on shows like CBS This Morning in November 2019, but what was once the size of a toolbox has been shrunk to a quarter the size of a pack of cigarettes.
“By decreasing the thermal mass of the sensor, we decreased the amount of energy required to operate the sensor,” said Gregory. “We started with a thermal mass on the order of grams. Now the thermal mass of our sensor is on the order of micrograms.”
One of the keys to making a device as small and powerful as Gregory’s is finding the right battery.
“We have partnered with a company that manufactures very thin, low mass batteries in Colorado, ITN Energy Systems,” said Gregory. “They make lithium batteries that are no thicker than a piece of paper. The process has been to find the right partners, which helps us improve our catalysts and our sensor platform.”
Pass the test
In March 2021, the Naval Research Laboratory brought its mobile test unit to the URI’s W. Alton Jones campus to put the explosives sensors of Gregory and others to the test.
“They set up a field test outside using their vapor test bench,” Ricci said. “They were able to select an explosive molecule and deliver it to the sensor system. Knowing what the level was, they wanted to see how our sensor would react. One of the tests was at the part per quadrillion level.”
Stay one step ahead
While the bad guys have developed new explosives or new ways to improvise on existing ones, the good guys have tried to stay one step ahead.
“The Department of Homeland Security has asked us to be flexible enough to anticipate and adapt to emerging threats that may arise several years later,” said Gregory. “We can tune our catalysts for a specific molecule that’s the current threat. That’s what we do with biomarkers. That’s what we do with drugs. What’s good about this platform is. is that it is flexible. “
The sensors developed by Gregory and Ricci have been tested and improved over a long period. The professor’s research was initially funded 20 years ago by the Defense Advanced Research Projects Agency (DARPA), a research and development agency of the United States Department of Defense that is responsible for the development of emerging technologies for use by the military. .
After two years of funding from DARPA, the military funded the project for one year. The Department of Homeland Security has since provided funds.
“At the time, this research was very new and very different,” said Gregory. “DARPA funds high-risk, high-reward projects. We have shown that the gamble they took on our concept at the time has paid off.”
Michael Silevitch, Robert D. Black Distinguished Professor of Engineering at Northeastern University, has collaborated with Gregory on his research for over 10 years.
“This is revolutionary technology,” said Silevitch. “Otto’s work on chemical detectors has evolved to be ready for use in many applications, including the deployment of his sensors on a drone-based platform to help protect soft targets such as schools, shopping malls or places of worship.
Take the new steps
Now that the sensors are very small and light, they could be attached to drones, leading to many new applications.
“We spoke with drone companies about using our sensors on their drones,” said Gregory. “Drones need very light portable power supplies and you have to harness their wireless communication. This is a much different set of engineering requirements than using a robotic arm that the military is looking to use for. roadside IEDs. “
Gregory and Ricci also work on sensor arrays, to differentiate one explosive, or threat, from another.
“We will need a set of sensors to detect a specific explosive in the presence of other explosives or precursors,” Ricci said. “If there is a plume of three different explosives, we may have to identify one of the others.”
Ready to use
Now that the sensors have proven to be effective, their implementation in real situations is only a question of funding.
“Our sensor is not yet a standard commercial product, but we have a potential partner,” said Gregory. “We just need a customer to step up and say here’s an order for 1,000 of them, can you deliver them?”