High P erformanc e F lexible F abric E lec tronic s for Megahertz F requenc y C ommunic ations

Yiannis Vardaxoglou,

Loughborough University

Tilak Dias NTU

Rob Seager LU

ADVANCED THERAPEUTIC MATERIALS LTD

Our purpos e

To find the most

effective way to produce a textile antenna and its associated electronics and to integrate this antenna into textiles.

• 3 year project • Partnership

between industry and academia

• Technically challenging

• Commercial potential

T he P artners

• Loughborough University – antenna and microwave specialists

• Nottingham Trent University – textile material properties, performance and design expertise

• Defence Marine Systems – understanding of potential applications in defence and aerospace

• Advanced Therapeutic Materials Ltd – innovation in manufacturing of textiles

• Antrum Ltd – expertise in the commercialisation of antenna technologies

• Cash’s – mainstream woven fabrics supplier • IeMRC – invaluable investment and support

Many applications

• Search and Rescue • Defence • Sport and leisure • Healthcare • Aerospace • Emergency Services • Disaster relief

energy-scavenging nanofibers woven into clothing and textiles.

Why are we doing this ? Current antennas can be: • Bulky • Delicate • Heavy • Easily mislaid/forgotten • Unattractive • Expensive • Require user intervention • Life threatening

• Rigid antennas have been known to puncture life rafts.

E xamples of microwave fabric antennas and T x lines already publis hed

Embroidered Spiral CP Antenna

E mbroidery

Embroidering process in the textile industry in England, 1858

Commercial machine embroidery, 21st century

S ome of our challenges

• Good conductivity/low losses • Good edge definition • Repeatability in manufacture • Computer Aided Engineering (CAE) link between

electronic design and fabric production • Interconnection to traditional systems • Maintain a close watch on possible applications

and end users

Who is doing what….?

• NTU and LU are the main research sites • NTU are working on the production of fabrics

samples using conductive threads • LU are providing input in terms of design for

microwave circuits and measurements • Industrial partners are advising on

manufacturability and possible markets

S ome initial progres s …

• A major review of conductive threads has been undertaken

• Electromechanical testing of yarns commenced

• Samples of high frequency transmission lines have been produced

• Measurement apparatus to evaluate the samples and the threads has been constructed

• Range of microwave and DC measurements have been made

S ome initial progres s …

• Initial guidelines for optimising the performance of fabric conductor systems at microwave frequencies are in place

• Database of conductive yarns and their properties initiated.

• Microwave measurements to assess fabric based conductors and antennas have been defined

• Enhanced measurements techniques still need to be developed in the second year.

S ome initial progres s …

• Second generation antenna and transmission lines produced • Enhanced edge definition

and “quality” • Antenna resonant frequency • Some variation apparent

due to different stitching in the production process

Where are we going next?

• Development of more sophisticated microwave measurements • Loss terms by direct measurement

• Development of theoretical models now practical data is available • Relate yarn conductivity and production to parameters of a

solid conductor for microwave CAE • In longer term, produce a transfer of CAE data from

design to production • We are grateful to the IeMRC for the chance to

undertake this project

Our antennas will be better becaus e they…

• Integrate into clothing improves user comfort and makes it unlikely that the device will be left behind;

• Have the potential for miniaturisation; • are high-technology, easy-to-use, appealing to gadget enthusiasts and

technophobes alike; • Flexible systems are lighter and easier to transport and then deploy; • More aesthetically pleasing - can be integrated into fashionable

sportswear as easily as utilitarian uniforms; • Use less processing materials in manufacture