2010 – 2013
This three year project ran from October 2010 to October 2013, and the project team comprised Loughborough University (experts in wireless communications), Nottingham Trent University (expert in textiles), Advanced Therapeutic Materials Ltd, Defence & Marine System and Antrum Ltd. Professor Yiannis Vardaxoglou from Loughborough University and Professor Tilak Dias from Nottingham Trent University (NTU) were the Principal Investigators. The central goal of the project was to find the most effective way to produce a fabric antenna and its associated electronics, and to integrate this antenna into fabric. The project also explored the possible commercial applications and to actively disseminated its findings to academic and non-academic communities.
The team considered various ways to create the antenna: weaving, sewing, knitting and embroidery, and investigated the suitability of available equipment to employ these techniques. Embroidery was chosen for several reasons as it offered the greatest flexibility when developing a ‘pattern’ for the antenna, it provided greater control over yarn tension when compared to weaving and knitting, it was easier to combine an embroidered antenna with a fabric substrate, and embroidery was the technique which could be mass manufactured most cost effectively. Throughout this process the team (particularly NTU) worked closely with embroidery machine manufacturers and formulated innovations to conventional embroidery machines to enable them to process conductive yarns consistently without undue tension and frequent breakages at high production speeds.
Whilst developing the embroidery process the team also trialled different transmission lines and the effects of different stitch directions and densities to identify the optimal combination. This process of elimination resulted in the design of ‘patterns’ for two functionally viable antennas.
The next priority was to identify the most appropriate fabric for the antenna to be embroidered onto. A range of military fabrics (secured from a supplier to the military) and denim were tried. Different layering combinations were tested to ascertain the most stable combination to support the antenna. Alongside this process the team were keen to attempt a knitted substrate and ground plane thereby creating the first completely fabricated antenna as opposed to simply appliqueing an antenna onto fabric.
This research was funded through the EPSRC Innovative Electronics Manufacturing Research Centre (IeMRC) under grant number SP/02/5/10.
Details of this innovation are available in the following article: ‘Embroidered Wire
Dipole Antennas Using Novel Copper Yarns‘