Polymer Centre research highlight – March 2012

Posted on Tuesday, March 13th, 2012 in Publications| Share this article
Dr Patrick Smith

University of Sheffield engineer, Dr Patrick Smith, has reported the results of research to exploit ionic liquids as potential transparent conductive materials in flexible electronic devices, such as flexible displays and photovoltaics, electronic textiles, sensory skins and active antennas.

Currently, transparent conductive materials are essential in electronic devices such as sensors, displays, and solar cells. The material of choice for these devices are conductive oxides such as indium tin oxide. These oxides are brittle and can easily crack under strain; more importantly though, they are becoming increasingly expensive due to scarcity.

Ionic Liquids are salts that are molten at their operating temperature (e.g. room temperature). They have a high potential to replace conventional solvents and task-specific liquids for application in catalysis, synthesis, gas absorption, or analytics. Their high ionic conductivity, transparency, low vapour pressure, and good chemical and thermal stability make them extremely attractive and of great interest for use in flexible electronic devices.

The work involved mixing ionic liquids with acrylate based monomers, inkjet printing microstructures and UV curing. The highly tunable system allows for optimisation of properties by using different types and amounts of ILs and monomers and the lack of solvent minimises processing issues. The method is a valuable, new process for the fabrication of inkjet printed ionic liquid-polymer gel microstructures with high-resolution, good electrical conductivity, optical transparency, and mechanical flexibility for use in electronics.

Original Publication:  Solvent-free inkjet printing process for the fabrication of conductive, transparent, and flexible ionic liquid-polymer gel structures. Loffelmann, U.; Wang, N.; Mager, D.; Smith, P.J.; Korvink, J.G. JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS 2012 Volume: 50   Issue: 1   Pages: 38-46.

For more information, please contact Dr Joe Gaunt at the Polymer Centre.