18 December 2017

Researchers develop successful proof of concept

Invisible label to combat counterfeit pills and spoiled food

Principle of the invisible and biodegradable label to ensure the safety of food products and pharmaceuticals

Together with a colleague at TU Delft, researchers from Utrecht University have developed an invisible and biodegradable label to ensure the safety of food products and pharmaceuticals. A unique barcode indicates that the product actually originated from the manufacturer whose name is on the package. Built-in sensors can detect whether the product was not sufficiently refrigerated during transport or storage, while another informs the user of a possible bacterial contamination. The researchers are now collaborating with manufacturers to facilitate industrial applications of the label. The results of their study were published in the scientific journal Small.

Expensive chemotherapy medication that turns out to contain counterfeit pills, or food products that have gone bad because they were not refrigerated during transport. How can a salesperson or consumer be sure that the product actually meets the advertised quality standards? As global trade networks have expanded, manufacturers are looking for ways to provide consumers with such a guarantee, but existing systems are far from water-tight. One solution involves unique hologram stickers on packaging, but these have proven to be all too susceptible to fraud.


Researchers Burak Eral and Ivan Rehor from the group of Willem Kegel’s at Utrecht University came up with an idea for a product label that is so small that it can be applied to a pill or a food product without being directly visible. The label should also be easy to scan, so that salespersons and consumers can test themselves whether the product is in order. This idea combines a microfluidic technology Burak Eral had helped to develop at the Massachusetts Institute of Technology in the United States, with advanced biodegradable hydrogels, developed at the Department of Pharmaceutics by Tina Vermonden and Wim Hennink.

Difficult to counterfeit

The tiny label is made from a biodegradable hydrogel and measures only 0.1 x 0.03 x 0.025 mm in size. This is so small that it cannot be seen by the naked eye. The label bears a ‘barcode’ in a form of 32 binary digits, which makes it possible to create 4.3 billion unique labels. The advanced technological expertise necessary to perform this process, makes it difficult for criminals to counterfeit such a label. Plus, the label is applied to the product itself, which makes it even harder to commit packaging fraud.

Miniature sensors

The label is also equipped with two miniature sensors. One changes colour if the pH of the product changes, which is often an indication of bacterial contamination. The other sensor indicates whether the product has exceeded a certain temperature by causing the bottom of the label to disintegrate. 


The bar code and the sensors require a microscope to read them, so for field applications a microscope attachment is fitted to a smartphone camera. A photo of the product is then image processed to determine whether the product is authentic or fake, properly refrigerated or not, or poses a risk of bacterial infection.

Further development with industrial partners

During the course of the research project, Burak Eral received an appointment at TU Delft. He continued to act as the project leader, but most of the development of the proof of concept was conducted in Utrecht by Sustainability and Marie Curie Fellow Ivan Rehor. Eral will now continue with the development of the label in cooperation with industrial partners.


Biodegradable Microparticles for Simultaneous Detection of Counterfeit and Deteriorated Edible Products
Ivan Rehor, Sophie van Vreeswijk, Tina Vermonden, Wim E. Hennink, Willem K. Kegel, and Huseyin Burak Eral
Small, 2017, 13, DOI: 10.1002/smll.201701804 October 2017

This study was financed by a seed money grant from Utrecht University’s interdisciplinary research programme ‘Pathways to Sustainability’. 


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