Nosang Vincent Myung has been a chemical and environmental engineering professor at UCR for 10 years. But it was at his previous position, at the Jet Propulsion Laboratory (JPL) in Pasadena, that he learned the most important lesson on presenting his research. Everything JPL did had to result in a concrete application for the space program, so Myung learned that theory alone wouldn’t cut it. “You cannot go with a half-cooked idea to show to people,” he declares, flashing his bright smile. “You’ve got to go all the way: ‘Here’s a complete prototype.’”
That’s the approach he took with his most significant invention so far: a tiny nanosensor that functions as an electronic nose, detecting chemical compounds in the air. The most recent version, developed by Nano Engineered Applications, Inc., could be the basic platform for any number of applications that involve sniffing out airborne chemicals. “Anything a nose can do, this can do,” Myung says.
The main piece of nanoengineered hardware looks like a perforated, tubular necklace string. By assembling beads in different configurations, the tube can be made to detect different chemicals. “This is a single-walled carbon nanotube 1.4 nanometers in diameter,” Myung says. “Then we put beads on it, and depending upon what bead and how you put it, it senses differently.” The process for creating the structure is simple electroplating, “except the scale is very small,” he says. “We deal with a single drop.”
At first, the development of the sensor itself was the goal, not the detection a specific chemical. “The vision was, let’s make a sensor the works really well, and not have a specific objective,” Myung says. Later on, the sensor could be attached to various kinds of devices, including robotic ones, that “tell you what the surrounding gas is, what you’re exposed to.”
Myung went on to create working prototypes that connected his nanosensor to a computer that could analyze what the sensor “smelled.” Subsequent innovations will largely involve training a better computer “brain” to interpret the data that Myung’s hardware “nose” detects: “You need a specific algorithm to train the computer to recognize smells,” he says.
One possible agricultural application for the nanosensor has recently captured Myung’s imagination. A UCR entomology professor is working on a problem with Rwandan coffee, wherein some of it smells like potatoes after it’s roasted. An onsite sniffing gadget could end up saving a lot of money and trouble. “The idea is, if you if you can detect [what’s causing the strange smell], that will save a lot of money, because you’re not going to ship it all the way to the United States and roast it.”
Possible law-enforcement applications include drug- or bomb-sniffing robots. “OK, we developed a nose. A smartphone has an eye, so we just have to put on the legs. So now, I call it an electronic sniffing dog. Places you don’t want to go, instead of sending a dog, you can send this robot.”
The sensor is small enough to be wearable in a clip or button, which could then connect to a smartphone via Bluetooth. Eventually, it could be made small enough to fit inside a phone. In addition to possible safety applications for agricultural and industrial workers, a personalized sensor also has crowdsourcing potential. “Imagine now you have a sensor to wear that tells you the air quality nearby,” Myung says. If this kind of data could be compiled, it would provide far more nuanced and accurate air-quality readings than the static sensors now in use.