Plasmonic ElectroChromic Materials for Dual-Band VIS-NIR Smart LABELling – PECLABEL

Active plasmonic devices have recently emerged as smart electronic and light management technologies with tunable optical characteristics. Highly doped metal oxide nanocrystals exhibit charge carrier densities leading to pronounced localized surface plasmon resonances (LSPR) in the near-infrared (NIR) spectral range. The resonance of free carriers can then be modulated through an electrochemical gating process, and the change in carrier concentration induces a shift in the LSPR frequency as well as a change in optical absorption, giving rise to plasmonic electrochromism. Such nanomaterials, well-known for their original and promising exploitation in advanced glazing devices (especially as smart windows), also present a strong potential for smart display and labelling devices typically involved in applications related to intelligent packaging, environmental monitoring, disposable diagnostics and dynamic road signs, among others. So far, many electrochromic label systems are based on organic and polymer compounds: despite their easy processability, versatility and high control on optical properties, these somehow lack of robustness and their stability to long-term on/off commutation as well as recyclability are questionable, especially in harsh environments (heat, humidity, stress). In this context, there is a critical need for more durable formulations, increased chemical, thermal and mechanical stability as well as higher levels of coloration efficiency and stability tenue.
The PECLABEL project aims at developing an innovative technology of smart electrochromic labelling for intelligent packaging and other electronics-related applications, based on inorganic metal oxide nanomaterials. Plasmonic electrochromic nanostructures based on aluminium-doped zinc oxide AZO, tin-doped indium oxide ITO, and substoichiometric tungsten oxide WO3-x will be chemically synthesized and characterized for being processed into thin functional films onto flexible substrates (including bio-based candidates), then manufactured into active demonstrator devices. Materials formulations will be obtained as printable, eco-conceived, low-toxic inks, and the manufacturing processes will be made compatible with standard graphic printing, leading to thin, flexible, robust, and ultra-low power smart labelling devices. These can be produced into a wide range of different shapes, patterns and sizes, offering many advantages for product design and integration. Such novel metal oxide inks will further be printed as workable electrochromic labelling devices, notably as colour tuneable QR codes, towards further applied integration in intelligent packaging systems. New functionality and selectivity in the NIR spectral range, with a tuning capacity being independent of the VIS behaviour, will also foster other interesting innovative developments in the fields of glazing devices (smart windows), security, military camouflages, smart textiles, (bio)sensing and telecommunications.
PECLABEL relies on strongly innovative and ambitious concepts and approaches, sustaining responsible research, design and characterization of novel functional materials for smart energy- and electronic-related applications. The project involves one University (University of Liege), three research/industrial centres (CNRS-ICMCB, LEITAT and VTT) and three small- or medium-sized enterprises (Color Sensing, Optitune, NordicID) being based in four different countries (Belgium, France, Spain and Finland), therefore implying actors throughout the whole R&D process and value chain. The project has a beginning TRL of 2, starting with the formulation of the dual-band VIS-NIR smart labelling technology concept from the synthesis of novel nanostructures of plasmonic electrochromic materials. It will end with a TRL of 6, through the demonstration of the technology in an industrially-related environment by exploiting advanced approaches of upscaled demonstrator manufacturing with wireless powering aptitudes.