Smart tags are dynamic data carriers that enable the user to access updated lifecycle data based on changes in the environmental conditions around the item that contains the tag. This is specifically useful for digital product passport (DPP) users that can use this dynamic lifecycle data to make decisions at product end-of-life. The smart tags can, for example, inform if the item has been exposed to conditions that make the item unsuitable for reuse or repair, thus advising the user to direct this item for recycling. Examples of possible use cases include e.g. textiles and textile fibres, electronic products, and batteries.
Technically smart tags are visible or electronic tags that contain environmental sensing functions. Therefore, a smart tag consists of (1) an identification element, such as a 2D bar code or an RFID tag, and (2) a sensing element, such as a visual or an electronic sensor. Combined these two properties offer context-aware services to the end users. VTT has developed a humidity sensing visual smart tag in DigInTraCE project (Figure 1). More details of this concept can be read in our recent open access journal paper with DPP for electronics sector as a case study: https://doi.org/10.1007/s43615-025-00500-y.
Figure 1. Principle of a visual smart tag. The blue bar at the bottom of the 2D bar code is the visual sensor that changes its colour (in this case from blue to yellow) when exposed to a relative humidity above a pre-defined threshold. The software app used to read the tag can detect the colour of the sensor area and tailor the digital information given to the user based on the state of the sensor.
Connecting smart tags with standardised dataspaces is an important feature of dynamic DPPs. These secure, interoperable data ecosystems enable controlled data sharing and ensure data sovereignty and compliance with EU regulations such as the newly enforced Data Act. For DPPs, dataspaces can provide a trusted infrastructure where manufacturers, suppliers, and recyclers can seamlessly exchange product lifecycle data but still maintain control over who can access their data and under what conditions. In practice, companies cooperating in a dataspace adopt common data models, use secure identification and authentication mechanisms, and agree to governance rules that define how data can be shared and used. These rules are then automated using specific smart contracts, eliminating the need for manual intervention and reducing administrative burden and integration costs. Dataspaces can thus facilitate business-to-business industrial data sharing which is a central prerequisite for well-functioning and adaptable DPPs.
This blog post was created by VTT partners: Liisa Hakola, Kristiina Valtanen, Maria Smolander
