Printed electronics are expected to meet an increasing demand for improved functionality and autonomy of products in the context of Internet-of-Things. With this trend, the environmental performance of novel technologies is of growing importance. The current study presents the life cycle assessment of two novel devices: an anticounterfeit label based on the electrochromic display and a shock-detection tag based on the piezoelectric sensor, designed for the use in packaging of pharmaceuticals and luxury items to improve the safety and accountability in the supply chain. The devices are manufactured by means of energy-efficient printing techniques on a low-cost flexible and recyclable paper substrate. Comprehensive cradle-to-grave analysis contributes to industrial-scale energy and material life cycle inventories and identifies the main impact hotspots evaluated for a broad range of categories of the ReCiPe midpoint (H) impact assessment method. Results show that major impact burdens are associated with the near-field communication chip and radio-frequency identification antenna, while the impacts of solvents, process energy, electrochromic display/piezoelectric sensor, Li-ion battery, and substrate are comparatively small. In terms of their global warming potential, both the anticounterfeit label and shock-detection tag embody around 0.23 kg of CO2-equiv. Several material-use reduction and material-substitution strategies are quantified and discussed for their potential to reduce high impacts of the antenna.

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The use of printed paper electronics in consumer goods is expected to experience a mass development in the next future. The ink used in these devices contains silver nanomaterials that may be released in the environment at the product end-of-life.We report here the first evaluation of the fate of silver during a pilot-scale recycling of printed paper electronics, made of paper printed with a cellulose nanofibrils-silver nanowire ink. We show that the released effluents are mainly free from silver, which is retained in the pulp conserved for recycling. We use atomic force microscopy experiments to show that this strong pulp-silver bond is due to the embedding of the silver nanowires in the pulp by coils of cellulose nanofibrils. We propose an estimate of the resulting adhesion stress of the nanowires to the ink, high enough to keep the silver inside the pulp during the recycling procedure.