SMU student developer of tiny pH sensor could be next-generation freshness predictor for packaged foods
Forget the expiration date on salmon or yogurt. A graduate student at SMU (Southern Methodist University) has developed a miniature pH sensor that can determine in real time when food has gone bad.
The flexible pH sensor is only 2 mm long and 10 mm wide, allowing the sensor to be integrated into current food packaging methods such as plastic packaging. The industry typically measures pH levels using very large meters, about 1 inch long and 5 inches high, making them suitable for inclusion in all packages of food to monitor food freshness in real time. Is not …
“The pH sensor we developed works like a small wireless radio frequency identification device, similar to what you find inside your luggage tag after being checked at an airport or SMU ID. Every time food packages with the device pass through checkpoints such as distribution centers, ports, gates and supermarket entrances, they can be scanned and the data sent back to the server to track pH levels. A PhD student at SMU’s Lyle School of Engineering and the primary creator of the device: “Such a configuration enables continuous pH monitoring throughout the journey from farm to consumer’s home.” It will allow us to accurately detect freshness limits.”
According to the Food and Agriculture Organization of the United Nations, about 1.3 billion tonnes of food produced worldwide go uneaten every year. Feeding America estimates that nearly 40% of food in the United States (about 130 billion meals) is wasted.
Creating the device was personal to Chawang, an electrical and computer engineering graduate student from Nagaland, a remote region of India whose population relies heavily on agricultural crops.
“Nagaland’s food waste means extra fieldwork for undernourished children and the elderly to make up for the loss,” Chawan said. “The need to prevent food waste has led me to think of devices that are inexpensive to develop, low effort, disposable, and capable of detecting freshness levels.”
Food waste not only leads to food insecurity and loss of profits for food manufacturers, but also has a negative impact on the environment. As the U.S. EPA reported in 2021, shipping all leftover food in the U.S. emits roughly as much carbon dioxide into the atmosphere as 42 coal-fired power plants.
In the Institute of Electrical and Electronics Engineers (IEEE) Big Ideas Competition at the 2022 IEEE Sensors Conference, Chawang was the J.-C. Chiao, Mary and Richard Templeton Centennial Chair and the Lyle School of Electrical and Computer Engineering. Professor.
Usage
Chawang explained that food freshness levels are directly correlated to pH levels. For example, food with pH levels higher than the normal range indicates that the food is spoiled. This is because fungi and bacteria thrive in high pH environments. Sudden pH changes in food storage during production and shipping can therefore indicate possible food spoilage.
The pH level is measured by the concentration of hydrogen ions contained in a substance or solution.
Since hydrogen ions are charged molecules, the electrode in Chawang’s pH sensor detects the charge created by the concentration of hydrogen ions in the food and uses what is known as the Nernst equation to determine the level of pH. can be converted to a value.
Chawang said the pH sensor has been successfully tested on foods such as fish, fruit, milk and honey. More tests are in the works.
The sensor is made from a very small amount of biocompatible material and uses printing technology on a flexible film.
“The whole process is similar to printing a newspaper. The process does not require expensive equipment or a semiconductor cleanroom environment,” says Professor Chiao. “Therefore, the cost is low and the sensors can be disposable.”
Chiao and graduate student Chawang are investigating whether the electrode device they developed to monitor food could also be used to ensure reliable fermentation of cheese and wine. What’s more, if the same technology were used on the skin, it could detect early warning signs of sepsis or wound infection, Chawang said.
Chiao, who joined the SMU faculty in 2018, is widely recognized for his work on using electromagnetic waves in medical applications such as closed-loop pain management systems and gastric motility management.
Original: Are you skeptical about ‘use by’ dates on groceries?
Than: Southern Methodist University
