## 3 Materials and Methods  
### Samples under Investigation  
The samples chosen for this study should reflect many different structural and material properties: nanofiber mats are very thin and have small pores in the nanometer range, while crocheted fabrics are relatively thick and have large holes in the range of several millimeters. Metalized woven fabrics have a homogeneous conductive coating, while 3D-printed conductive or magnetic materials usually show nonconductive or nonmagnetic areas next to percolation paths but have smaller pores than crocheted fabrics. Conductive coatings on nonconductive textile fabrics will lead to relatively homogeneous conductive properties of the samples, but they will have much higher resistivity than the metallized fabrics. By choosing these samples, a broad variety of different materials and structural parameters is tested. Nanofiber mats were produced by the needleless electrospinning machine NanoSpider Lab (Elmarco, Czech Republic) from a spinning solution of 14% poly(acrylonitrile) (PAN, X-PAN, Dralon, Dormagen, Germany) in dimethyl sulfoxide (DMSO, minimum 99.9%, S3 Chemicals, Bad Oeynhausen, Germany) with additional nickel ferrite nanoparticles (Fe\({}_{2}\)O\({}_{3}\)/NiO, Merck KGaA, Darmstadt, Germany) in different mass ratios. The applied coatings are PEDOT:PSS (Orgacon S305), an intrinsically conductive polymer, and Powersil 466 A/B (Wacker Chemie AG, Munchen, Germany), a liquid silicone rubber based on poly(dimethylsiloxane). The conductive yarns used in this study are Shielddex 235/34 dtex (Statex, Bremen, Germany), containing silver-coated polyamide 6.6 fibers, and S-Shield Nm 50/2 (Schoeller,Bregenz, Austria), containing 80% polyester (PES) fibers and 20% steel fibers, which is also ferromagnetic. The commercially available woven fabrics under examination are Ripstop Silver Fabric (Less EMF, NY, USA) and Pure Copper Polyester Taffeta (Less EMF). All 3D-printed samples were produced by an Orcabot XXL Pro 2 (Prodim, the Netherlands) fused deposition modeling (FDM) printer, preparing 3 layers in \(\pm\)45\({}^{\circ}\) orientation with an overall thickness of 0.6 mm. The polymers used for 3D-printed samples are pure poly(lactic acid) (PLA) (Grauts GmbH, Lohne, Germany), conductive PLA (Proto-pasta, Vancouver, Canada), and magnetic PLA (Proto-pasta). The investigated samples are shown in Table 1. Microscopic images were taken with a Camcolms2 digital microscope. Sheet resistance values of the samples were measured with a 4-point MR1 measurement system with special textile electrodes (Schuetz Messtechnik, Teltow, Germany). \begin{table}
\begin{tabular}{c c} \hline \hline
**Name** & **Description** & **Micrograph** \\ \hline PEDOT:PSS & Cotton woven fabric with PEDOT:PSS coating (40 warp threads/cm, 40 weft threads/cm) \\ \hline Powersil & Cotton woven fabric with Powersil coating (40 warp threads/cm, 40 weft threads/cm) \\ \hline PEDOT:PSS/Powersil & Cotton woven fabric with PEDOT:PSS and subsequent Powersil coating (40 warp threads/cm, 40 weft threads/cm) \\ \hline \end{tabular}
\begin{tabular}{c c} \hline \hline
**Conductive yarn** & Hand-crocheted fabric from 2 Shielddex yarns (2.6 wales/cm, 2.2 courses/cm) \\ \hline \end{tabular}
\begin{tabular}{c c} \hline \hline
**Magnetic yarn** & Hand-crocheted fabric from 2 S-Shield yarns (2.6 wales/cm, 2.2 courses/cm) \\ \hline \end{tabular}
\end{table} 
Table 1: Samples under investigation. The long side of all images is 8 mm in length.