A Biodegradable, Edible Microsensor For Food Monitoring
Always refrigerate or freeze meat, poultry, eggs, and other perishables as soon as you get them home from the store. Never let raw meat, poultry, eggs, cooked food, or cut fresh fruits and vegetables sit at room temperature more than two hours before putting them in the refrigerator or freezer. And oh, reduce that to one hour when the temperature is above 90° F.
All this is such a pain. And this whole temperature game goes awry during transit.
Don’t you worry though, scientists are on the case.
ETH researchers have now developed a biodegradable temperature sensor that could be fitted to fish or other food products to monitor their temperature.
Microsensors are already in use for various purposes. They come with precious metals that are both helpful and toxic to both humans and environment. They aren’t suitable for medical applications involving direct contact with the human body or for inclusion in food products. Therefore, they are the subject of interest for various scientists for applications in industries and research.
But now, this team has developed an ultra-thin sensor out of materials that a human can digest safely. The sensor is made out of
potato starch to create the polymers being packed to the microsensor. The overall composition of the microsensor complies with EU and US foodstuff legislation.According to Giovanni Salvatore, one of the researchers in the team, these biodegradable microsensors have a bright future. He also cited one potential application: “In preparation for transport to Europe, fish from Japan could be fitted with tiny temperature sensors, allowing them to be continuously monitored to ensure they are kept at a cool enough temperature.”
He further said, “Our sensors are suitable for use in foodstuffs and are no threat to consumer health. The sensors also need to be small, robust and flexible enough to survive in containers full of fish or other food products.”
Salvatore said, “It’s relatively easy to extend the operating life by adjusting the thickness of the polymer. A thicker sensor would be less flexible, however. The current sensor is so thin. It continues to function even if it is completely crumpled or folded. Even when stretched by around 10% of its original size, the sensor remains intact.”
The scientists have managed to build a sensor that’s only 16 micrometers thick — for comparison, a human hair is 100 micrometers or so. This filament is made of magnesium, which is “an important part of our diet.” Also used are silicon dioxide and nitride, which are harmless, and a compostable polymer made of corn and potato starch holding it all together. The whole thing can be bent, stretched, even crumpled up and it’ll still work.
So you slap a few of these on some randomly selected apples, fish, bananas, etc, and put them in the truck or boat. You can then check the actual temperature of the food (as opposed to the air above the pile of fish) from outside the refrigerated compartment.
To save energy, the sensor is connected to an external micro battery using ultra-thin, biodegradable zinc cables. These cables can transmit temperature data to a computer within a range of 20 meters.
Further research is required before the sensors can be produced for the mass market. “Once the price of biosensors falls enough, they could be used virtually anywhere,” said Salvatore.
