This thesis describes direct write printing methods to achieve flexible electronic devices on fabrics by investigating, low temperature process; and functional conductor, insulator and semiconductor inks. The objective is to print flexible electronic devices onto fabrics solely by inkjet printing or pneumatic dispenser printing. Antennas and capacitors, as intermediate inkjet printed electronic devices, are addressed before transistor fabrication. There are many publications that report inkjet printed flexible electronic devices. However, none of the reported methods use fabrics as the target substrate or are processed under a sufficiently low temperature (≤150 oC) to enable fabrics to survive. The target substrate in this research, standard 65/35 polyester cotton fabric, has a maximum thermal curing condition of 180 oC for 15 minutes and 150 oC for 45 minutes. Therefore the total effective curing time is best below 150 oC within 30 minutes to minimise any potential degradation of the fabric substrate. This thesis reports on an inkjet printed flexible half wavelength fabric dipole antenna, an inkjet printed fabric patch antenna, an all inkjet printed SU-8 capacitor, an all inkjet printed fabric capacitor and an inkjet printed transistor on a silicon dioxide coated silicon wafer. The measured fabric dipole antenna peak operating frequency is 1.897 GHz with 74.1 % efficiency and 3.6 dBi gain. The measured fabric patch antenna peak operating frequency is around 2.48 GHz with efficiency up to 57 % and 5.09 dBi gain. The measured capacitance of the printed capacitor is 48.5 pF (2.47 pF/mm2) at 100 Hz using the inkjet printed SU-8. The capacitance of an all inkjet printed flexible fabric capacitor is 163 pF (23.1 pF/mm2) at 100Hz with the UV curable PVP dielectric ink developed as part of this work.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:595578 |
| Date | January 2014 |
| Creators | Li, Yi |
| Contributors | Torah, Russel |
| Publisher | University of Southampton |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | https://eprints.soton.ac.uk/363098/ |
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