Silver-based reactive ink for inkjet-printing of conductive lines on textiles

- A reactive silver ink, containing no particles but complexed silver, was optimized for inkjet printing on textiles.
- After printing the silver ink can be reduced at only 50°C to metallic silver nanoparticles forming a conductive network.
- For demonstration a microcontroller and a pulse sensor were successfully connected by an inkjet printed circuit on textile.

Silver is the material of choice for printed electronics. However, dispersed silver particles can block the fine nozzles of an inkjet print head and after printing the patterns have to be sintered at elevated temperatures to provide high conductivity. In this work we investigated and optimized the printing of a reactive silver ink which contains silver in complexed form, therefore avoiding disadvantages of particle dispersions. After printing the complexed silver is transferred into metallic by evaporating the complexing ligands at 50 °C. The ink contains around 11% silver and has a surface tension of 26 mN m− 1. It is stable for at least 1 month at room temperature and for at least 3 months at 2-8 °C. The ink was tested on several substrates and an application on textile is shown. The inkjet printed electronic circuit paths on the fabric withstand washing tests, moisture, and heat as well as crumpling.

126