Smart eco-label set to revolutionize supply chains
Researchers from Empa, EPFL, and CSEM have developed a battery-free, fully biodegradable sensor label that monitors temperature and humidity and documents whether cold chains have been broken—for example, for vaccines or food.
A novel, smart label measures temperature and relative humidity in real time and detects when a defined temperature threshold has been exceeded. It thus closes a key gap in global supply chains, where sensitive goods such as medicines or perishable foodstuffs have so far only been checked at specific points. The Greenspack project was developed over the past four years by Empa, EPFL, and CSEM and funded as part of the BRIDGE Discovery Program by SNF and Innosuisse.
Technically, the sticker is similar to an RFID system: conductive tracks are printed on a special biopolymer cellulose substrate, combining ohmic and capacitive elements to form resonant circuits. When the label is read contactlessly, the resonance frequencies change depending on the ambient temperature and humidity, allowing measurements to be taken without a separate energy source. If the temperature exceeds 25 degrees Celsius, a tiny element in the conductor melts, irreversibly breaking the circuit—a clear signal that the shipment was once too warm.
Researchers see this as a lever for significantly reducing waste and the carbon footprint in logistics. Potentially damaged goods can be identified early on, stopped, or redirected to nearby locations if only their shelf life has been shortened. Depending on the material used, the temperature threshold can also be adjusted for frozen products or other sensitive applications.
The team placed particular emphasis on the ecological balance: the substrate and conductor tracks are designed so that the eco-label can be composted or recycled with cardboard after use. To this end, the researchers developed a new carrier material made of biopolymer and cellulose fibers, as well as a printing ink containing the biologically absorbable metal zinc. While CSEM worked on the design and readout technology, two EPFL researchers are driving forward commercialization in the start-up «Circelec.» In the future, the smart labels are also to be used as sensors in agriculture and environmental monitoring.
Source: Empa
This article originally appeared on m-q.ch - https://www.m-q.ch/de/smarte-oeko-etikette-soll-lieferketten-revolutionieren/
