Food, flowers, pharmaceuticals, and other perishables are next to worthless if they're about to spoil. Due to the unpredictable variables involved in shipping, expiration dates often can be unreliable. As a result, products that won't be fresh for long make it to retailers' shelves, while distributors toss away otherwise healthy items simply because their labels inaccurately say they're spoiled.
A team of engineering students from the University of Florida has developed a sensor that should combat these problems. The team's device, which is about the size of a half-dollar, monitors the product's temperature. It then merges its readings with an algorithm developed by university professor Bruce Welt that electronically mimics the spoilage characteristics of that particular product. The sensor communicates these results in real time via a wireless transmitter.
Current markers indicate spoilage through tags or labels that turn color. But these methods don't indicate when that spoilage occurred, nor do they say how much more time fresh goods have before they do spoil. Also, these tags must be customized to the products they're tracking, opening up possibilities for errors. And, temperature monitors don't always account for fluctuations within a shipment—say, a pallet of goods stacked near a vent spoiling at a rate that's different from goods buried under other crates.
The team's sensor accounts for more than temperature. It also tracks and interprets changes in humidity as well as shocks from drops and collisions. Retailers can use a laptop to verify the freshness of individual items in a shipment, selecting what's good and rejecting the rest instead of accepting or declining entire loads. In turn, this should lead to lower costs and better quality for consumers.
The sensor is battery-powered, and the team anticipates a lifetime of a year or greater. For communications, it relies on Dynastream's ANT Protocol, which the team chose for its low power requirements and reasonable range. The low-power TI MSP 430 microprocessor that drives the sensor offers a range of software compatibility and cost options. And, the team is developing custom software to communicate product-specific time, temperature, and perishable attributes.
Led by Bill Eisenstadt, associate professor of electrical and computer engineering, the six seniors on the team are now working with University of Florida business and law students to patent and market the device as part of the school's Integrated Technology Ventures program. The team also recently received a $15,000 grant to continue developing the technology this summer.
University of Florida
www.ufl.edu