Fabrication of Textile Antennas and Circuits With 0.1 mm Precision

Abstract

We present a new selection of E-fibers (also referred to as E-threads) and associated embroidery process. The new E-threads and process achieve a geometrical precision down to 0.1 mm. Thus, for the first time, accuracy of typical printed circuit board (PCB) prototypes can be achieved directly on textiles. Compared to our latest embroidery approach, the proposed process achieves: 1) 3 × higher geometrical precision; 2) 24 × lower fabrication cost; 3) 50% less fabrication time; and 4) equally good RF performance. This improvement was achieved by employing a new class of very thin, 7-filament, Elektrisola E-threads ( diameter ≈ 0.12 mm, almost 2 × thinner than before). To validate our approach, we “printed” and tested a textile spiral antenna operating between 1-5 GHz. Measurement results were in good agreement with simulations. We envision this textile spiral to be integrated within a cap and unobtrusively acquire neuropotentials from wireless fully-passive brain implants. Overall, the proposed embroidery approach brings forward new possibilities for a wide range of applications.