Wearable antenna makes it through the wash

1 min read

Researchers in the east Midlands have created a prototype antenna that can be embroidered onto clothing.

The antenna, developed over the past three years at the universities of Loughborough and Nottingham Trent, is claimed to be fully flexible, lightweight and water resistant. Immediate applications have been identified in the military and emergency services.

It is further claimed that the device could act as a viable alternative to monopole antennas, which Nottingham Trent’s Prof Tilak Dias said are bulky, heavy and prone to breaking.

Prototype fabric antenna
Prototype fabric antenna

Prof Dias, leader of the Advanced Textiles Research Group at Nottingham Trent, explained that modifications to embroidery machinery were essential in order to accommodate the conductive thread used to make the antenna and speed up the process for mass production.

The conductive thread is a polyamide yarn covered with a nano-coating of silver. Prof Dias explained that a key challenge was to minimise frictional drag that can cause the yarn to break at high speeds.

Prof Dias was reluctant to reveal finer details about modifications to the embroidery machinery but he did say that changes to different guides and tensioning devices within the machinery has resulted in a system that can be run at normal production speeds.

‘One of the key areas we had to take into account was the dimensions of this antenna, they have to be really precise,’ he said. ‘We had to improve the way we embroider to get there, so that we get the consistency in the sense of dimensions, and that the antenna is ‘clean’ [without frayed fibres].’

The antenna has been successfully wash-tested at different temperatures and spin-cycles and abrasion tests have been conducted also.

‘We really did our best to destroy the fabric,’ said Prof Dias.

Further testing of the antenna’s capabilities, such as working at MegaHertz frequencies, was carried out in Loughborough University’s anechoic microwave measurement chambers.

The team, including industrial partners, was able to produce the antenna with grant funding of £465,249 from EPSRC’s Innovative electronics Manufacturing Research Centre (IeMR