Recyclable Wireless Sensors on Biodegradable and Biocompatible Materials
Supervisor: Dr Benjamin King and Dr Mahmoud Wagih
Industry Partner: Nano Dimension Inc.
School: Engineering
Description:
Reducing e-waste while continuing to produce enough electronic components to meet the demand of the internet of things (IoT) age including a significant quantity of sensors for environmental monitoring, occupational health and safety, and diagnostics, requires a substantial shift in the way we approach electronics manufacturing and materials management. Printing electronics is an emerging manufacturing strategy for consumer electronics including RFID tags and sensors. Printed electronics represent a shift away from manufacturing of traditional silicon-based electronics and existing technologies employing nanomaterials. Progress has been made in printing electronics using inkjet printing, screen printing and gravure printing at modest temperatures, enabling the production of large-area electronics with substantially less energy input and emissions compared to silicon electronics. However, despite this progress, there are very few wireless systems on biodegradable substrates.
In this project, you will design a planar wireless radio frequency (RF) sensor based on a conductive polymer (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), widely used in thin-film electronics. To date, only a handful of RF sensors have been fabricated based on conductive polymers, primarily by drop-casting, which is a bench scale technique. Additionally, PEDOT:PSS RF sensors have been scarcely optimized using large-area fabrication techniques. The proposed devices have the potential to be integrated in world-leading printed electronics processes developed by the partner, Nano Dimension.
You will screen-print PEDOT:PSS films on to polyethylene terephthalate (PET), a recyclable substrate, by adjusting a range of parameters including print speed, number of print cycles, etc. to optimize the conductivity of the sensor tag and its sensitivity towards common analytes including humidity. The devices will be characterized, followed by recycling PEDOT:PSS and re-printing it on to the same substrate to be recharacterized to investigate losses in performance. In addition to optimizing a PEDOT:PSS screen-printing process for large-area electronics fabrication, this work will enable us to understand the relationship between print parameters, PEDOT:PSS thin-film structure, and sensitivity of resulting RF sensors.
Figure A) Schematic of a screen-printing process and B) of array of screen printed flexible conductive patches. Figure A adapted from Wagih et al. IEEE Journal of Microwaves, 2 (1), 2022, 162-173. 10.1109/JMW.2021.3126927. Figure B reproduced from Nature Communications, 7, 11650 (2016), 10.1038/ncomms11650.