Biodegradable smart tag from Empa, EPFL and CSEM enables real-time monitoring of sensitive goods

Inconspicuous: The biodegradable tag is as thin as a sheet of paper, but still able to measure the temperature and relative humidity. Image: Empa

(IN BRIEF) A collaboration between Empa, EPFL and CSEM has resulted in a fully biodegradable smart sensing tag designed to monitor temperature and humidity during transport and record whether critical temperature thresholds have been breached. Developed through the Swiss-funded Greenspack project and published in Nature Communications, the paper-thin sensor works similarly to RFID, using printed conductive circuits that change resonance in response to environmental conditions, enabling real-time tracking with no battery or silicon components. If temperatures exceed 25°C, a circuit melts, permanently indicating exposure — a feature valuable for sensitive goods such as food or medicine. The tag is made from cellulose-biopolymer materials and printed with zinc-based conductive inks, allowing it to be recycled or composted after use. The technology aims to cut waste, improve supply-chain traceability and support circular logistics, with commercialisation already underway through the spin-off Circelec.

(PRESS RELEASE) DÜBENDORF, 1-Dec-2025 — /EuropaWire/ — A research team spanning Empa, EPFL and CSEM has unveiled a new fully biodegradable smart sensor tag capable of monitoring temperature and humidity during transport – and crucially, detecting whether critical thermal limits have been exceeded. The technology, developed through the four-year Greenspack project, opens the door to a more sustainable and low-impact way of monitoring sensitive cargo, such as pharmaceuticals, vaccines and food products, without relying on silicon-based electronics or battery-powered chips. The findings have been published in Nature Communications, with financial support from Innosuisse and the Swiss National Science Foundation through the BRIDGE Discovery programme.

The paper-thin sensing label can perform continuous measurements throughout a shipment’s journey, rather than only at checkpoint scanning locations. It functions similarly to RFID technology: the tag contains printed conductive pathways that generate a unique resonance when exposed to an electromagnetic field. Because conductivity and capacitance shift depending on surrounding temperature and humidity, a reader can interpret those changes in real time to determine the conditions the shipment experienced – using no transmitter, no onboard electronics, and no stored energy.

Vast flows of goods circle the globe every day. They include particularly delicate shipments, such as certain vaccines, medicines and food products. Image: Adobe Stock

Researchers have also engineered the tag to remember whether a product has been exposed to unsafe temperatures. If the environment rises above 25°C, a miniature circuit element melts, permanently breaking a connection. Upon scanning, the tag will display evidence that a shipment has exceeded the safe temperature range. For pharmaceuticals, this information could determine whether items must be discarded or used more quickly. Such technology could help prevent spoiled goods from continuing along the supply chain, allowing redirection or earlier intervention, ultimately reducing waste and emissions resulting from compromised cargo.

Sustainability is central to the platform. The sensor substrate uses a biodegradable composite of cellulose fibres and biopolymers, while zinc-based inks form the conductive patterns. Once its function is complete, the entire tag can be composted or recycled with cardboard, reducing waste associated with conventional electronics. The consortium’s work also highlights the wider potential for green electronics, from agricultural field sensing to environmental monitoring applications. A start-up, Circelec, founded by two EPFL researchers, is now preparing to commercialise the concept, while the Empa team aims to expand research into biodegradable smart labels for wider industrial use.

Further information

Dr. Gustav Nyström
Empa, Cellulose and Wood Materials
Phone +41 58 765 45 83
gustav.nystroem@empa.ch

Dr. Gilberto Siqueira
Empa, Cellulose and Wood Materials
Phone +41 58 765 47 82
gilberto.siqueira@empa.ch

Dr. Danick Briand
EPFL, Soft Transducers Laboratory
danick.briand@epfl.ch

Dr. Oleksandr Vorobyov
CSEM
oleksandr.vorobyov@csem.ch

Editor / Media contact

Anna Ettlin
Empa, Communications
Phone +41 58 765 47 33
redaktion@empa.ch

Literature

J Bourely, N Fumeaux, X Aeby, J Kim, G Siqueira, C Beyer, D Schmid, O Vorobyov, G Nyström, D Briand: Ecoresorbable chipless temperature-responsive tag made from biodegradable materials for sustainable IoT; Nature Communications (2025); doi: 10.1038/s41467-025-65458-9

SOURCE: EMPA