Flexographic Printed Flexible Thermochromic Stickers for Smart Sensing Applications

• DOI: 10.1002/admi.202400972
• Publication Date: 2025-04-05T09:36:50Z
• Authors: M. Morais; J. Figueira; M. C. Corvo; M. Peixoto; D. Oliveira; A. Gonçalves; E. Fortunato; R. Martins; E. Carlos; J. V. Pinto
• Keywords: Thermochromism

Abstract The growing demand for thermochromic materials in areas such as food packaging requires the development of fast‐response and extended‐life materials. use metal cation‐ionic liquid complexes is increasing due to easiness tailor their properties, leading changes response. This work presents synthesis introduction 1‐butyl‐3‐methylimidazolium chloride 4‐chloronickelate ([BMIm] 2 [NiCl 4 ]) into water‐based inks. Formulations with varying concentrations (10–40 wt.%) are printed on tags thorugh a roll‐to‐roll process tested between 30–45 °C. Also, films one five layers analyzed color contrast different encapsulating studied improve films' robustness. optimal films, three ink 40 wt.% encapsulated Fixomull Transparent present enhanced fast response time. Red‐green‐blue analysis performed these revealing blue/red ratio 1.7 after heating at °C 30 min. paves way developing flexible stickers high contrast. innovative straightforward inks' production compatibility large‐scale manufacturing show promising future cost‐effective smart applications, visual indicators ideal consumption temperatures.