This is something new, for the very first time, researchers from the University of California at Berkley and National Chiao Tung University in Taiwan created a “smart cap” that can detect when milk is losing its freshness.
The lid uses 3D-printed electronic components that include circuits with wireless sensors that react to changes in electrical signals caused by the spread of bacteria.
Instead of squinting at the tiny printed sell-by dates on a milk container all you need to do is to tip the bottle so that the liquid comes into contact with the lid, which will change colour if there is a noticeable proliferation of bacteria.
This 3D-printing technology could eventually make electronic circuits cheap enough to be added to packaging to provide food safety alerts for consumers. You could imagine a scenario where you can use your cellphone to check the freshness of food while it’s still on the store shelves,” said Liwei Lin, senior author of the study
The researchers created their 3D-printed electronic circuitry by fusing traditional polymer materials with ‘sacrificial structures’ composed of wax. When the wax structures were removed, a liquid silver suspension was injected into the paths that were left. Once cooled, this formed the necessary metallic framework for the electronic circuitry to function.
The design of the sensor enabled the smart cap to detect changes in electrical signals stemming from increased levels of bacteria in a carton of milk, which the researchers left unopened at room temperature for 36 hours.
Milk suppliers would have to ensure that their milk is stored and shipped correctly as supermarket buyers will easily see if they are taking in a consignment of milk that is passed its sales date, and consumers won’t be at of risk buying milk that is not fresh. The technology used for the bottle top can be used for other food packaging as well.
As an after thought, the research paves the way for all kinds of basic electronics that could help us out in our day-to-day lives.
via Microsystems & Nanoengineering Journal