IMB-CNM PhD Thesis Defense: Development of Functional Inks and Printed Devices for Transient and Eco-friendly Electronics
By Tammy Sue Wuen Leung, predoctoral researcher
- Carme Martínez-Domingo (ICMAB)
- Eloi Ramon (IMB-CNM)
Disposable consumer electronics are the main cause of excessive electronic waste that drives the need for more sustainable systems. One way to mitigate this problem is by incorporating eco-friendly processes and biodegradable materials into the development of everyday electronics. This includes the adoption of inkjet printing coupled with low temperature sintering methods.
This thesis introduces a new class of inks named Metal Salt Decomposition (MSD) inks that were reduced using oxygen plasma sintering and chemical-light sintering. In the case of the former technique, a wide range of metal salts were tested based on their respective reduction potential and found to display good conductivity on non-planar and non-conventional substrates such as polymers, papers and textiles which formed conformal films regardless of the substrate rugosity. However, this technique paled in comparison to the latter where in situ Au film growth occurred when placed onto reducing substrate such as PVA developing a connected and highly conductive Au film. Although PVA could be used directly for its dielectric properties, this layer was further enhanced through the development of a PVA-based ion gel combined with a biodegradable choline-malate ion liquid. With this, a broad range of applications such as electronic devices such as conductive tracks, electrodes, strain sensors, biosensors, antennas, and transistors were demonstrated. It is believed that this work will have implications in the future of printed electronics for wearable applications, biomedical, and electronic fields.