Ms. Khengdauliu Chawang a graduate student at Southern Methodist University (SMU) has developed a miniature, disposable pH sensor that can be incorporated in food packaging to detect spoilage.  The sensor detects and measures the electrical activity associated with evolution of hydrogen ions accompanying spoilage. Low pH levels indicate spoiled food forming the basis of the surveillance system.

Commenting on her innovation, Ms. Chawang stated, “The pH sensors we developed work like a small wireless radio-frequency identification device, similar to what you find inside your luggage tag.”  She added, “Every time a food package with our device passes a checkpoint during shipping, logistics centers, or supermarket delivery they can be scanned and data can be sent back to a server tracking pH levels.

The sensor that is 2mm long and 10mm wide is compatible with flexible packaging. Sensors have been tested on a number of food items including fish, fruit, milk and honey and in addition they have potential medical and food-processing applications.