ARTIFICIAL NOSE "SMELLS" WHEN FOOD IS ABOUT TO GO BAD

Cameras gave computers eyes. Microphones gave them ears. Touchscreens gave them tactile perception. Now the Massachusetts-based company 2C2Sense has invented a tiny chip that gives computers a sense of smell.

The first goal of the company, says co-founder and CTO Jan Schnorr, is to use machines to sniff out spoiling food. And that could have a bigger impact than you might think.

"The company's goal is to make wireless sensor chips so cheap that they could be built into a product's packaging."

Food spoilage can be contagious. You know the saying "one bad apple can spoil the whole batch"? It's true. As fruit ripens, it releases a musky gas called ethylene. When fruits are exposed to ethylene, they ripen more quickly and give off more ethylene themselves, creating a domino effect that speeds up the ripening process for every piece of fruit nearby.

C2Sense's technology can detect ethylene even in trace amounts that a human wouldn't be able to smell, enabling food sellers to spot ripening food before it spreads. A wholesaler might use these sensors to monitor crates of fruit and move those that are starting to ripen before they spread ethylene to every other crate in the warehouse, while a restaurant might use a handheld device to pinpoint individual pieces of fruit before they spoil their neighbors.

The Smell-o-Meter in Every Home

Many of us already have rudimentary smell-o-meters in our homes. We call them smoke detectors and carbon monoxide alarms. Everything we can smell, from buttery popcorn to pine trees, radiates particles that trigger chemical reactions in the cells in our nasal cavity. Depending on the specific reaction, the cells then send signals to our brains. Carbon monoxide alarms and ionization smoke detectors work in much the same way: specific particles cause chemical reactions that change an electrical current in the device, which in turn triggers an alarm.

Sensors that are able to detect ethylene have been around for years, Schnorr says, but they've generally either been too expensive or unable to accurately detect ethylene outside the lab where they'll be exposed to numerous other similar gases. What C2Sense has done, he explains, is create an affordable sensor that's also sensitive enough to detect low levels of the gas without setting off false positives.

The secret is a brand new material that Schnorr and his research team invented while he was a chemistry PhD student at the Massachusetts Institute of Technology. The new material, which is cheap to synthesize, chemically reacts to ethylene. Schnorr's team uses this material as a resistor in a tiny electrical circuit. As the number of ethylene molecules increase, the material's conductivity changes and the electrical current changes accordingly. They can then measure the current to gauge the level of ethylene in the sensor's vicinity. Now the team has modified the material to detect other gases, such as the amines released by meat or ammonia. Their current prototype is able to detect up to four different types of gas on a single chip.

Last year Schnorr and his PhD supervisor Timothy Swager decided to spin the company out of MIT. "At first I thought I'd follow the typical path of working for a big company," he says. "But then towards the end of my PhD we came across this idea of that seemed worth commercializing." Last month the the company received a $350,000 grant from Breakout Labs, philanthropic fund started by PayPal co-founder and early Facebook investor Peter Thiel that helps scientists turn their research into companies.

Schnorr says the company's goal is to make wireless sensor chips so cheap that they could be built into a product's packaging, or incorporated into produce bags at the grocery store, without adding any noticeable cost at the register. Customers could then scan these chips with their phones to get a freshness reading. Now we just need a machine that can taste our food for us before we buy it.