Microsensors are already used in a variety of applications, such as the detection of poisonous gases. However, they often contain precious metals that are harmful to the environment and health, making them unsuitable for contact with the human body or food products.
Scientists at the Federal Institute of Technology in Zurich (ETH) have now developed a microsensor made of biodegradable non-toxic materials. They created the sensor by encapsulating a superfine, tightly wound electrical filament made of magnesium, silicon dioxide and nitride in a compostable polymer.
Only 16 micrometers thick, the sensor developed by the Zurich researchers is significantly thinner that a human hair. It weighs no more than a fraction of a milligram. Because it can currently function for one day, it could be used in the delivery of fish from Japan to Europe.
“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,” explained Giovanni Salvatore, a postdoctoral researcher at the ETH.
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.
The sensors could bring food products into the Internet of Things (IoT). Their use would not be limited to temperature measurement, however. Similar microsensors could be deployed to monitor pressure, gas build-up and UV exposure.