at position labeled 1 (labeled 2). And FIGS. 9G-9I are schematic illustrations of change in signal transmission |S$_{2i}$| as a function of gap width from dl = 0, d2 = 6, and d3 = 2, respectively, according to embodiments of the present disclosure. [00144] Unlike conventional conductive textiles, signal propagation on metamaterial textiles is robust to discontinuities in the underlying conductive structure. Simulations illustrated in FIGS. 9A- 91 show that the transmission efficiency across a 1cm gap in the direction of propagation ( ) is greater than - 7 dB; the structures can also be discontinuous in the transverse y) or vertical (z.) directions with transmission efficiencies greater than - 3 dB and -10 dB, respectively, for a 1 cm gap. [00145] FIG. 10A is a schematic illustration of Bluetooth signal propagation across a gap between two textiles, according to embodiments of the present disclosure. FIG. 10B is a schematic illustration of RSSI measured from a wireless receiver placed near the upper textile as the gap distance between the textiles is increased, according to embodiments of the present disclosure. FIG. 10C is a schematic illustration of Bluetooth signal propagation on textiles cut with scissors, according to embodiments of the present disclosure, and FIG. 10D, is a schematic illustration of RSSI as a function of numbers of cuts. Red bar shows RSSI measured in absence of the metamaterial textile. [00146] Experimental measurements of wireless Bluetooth transmission along the metamaterial textile show a comparable transmission efficiency for a vertical gap as well as no detectable decrease in signal strength when the textile is cut at multiple locations (see FIGS. 10A, 10C). Such contactless transmission along the metamaterial textiles allows signals to efficiently couple between nearby structures and propagate from one article of clothing to another. [00147] Reference is now made to FIGS. 11A-11B, which are schematic illustrations of instantaneous electric field amplitude and time-averaged power density S (logarithmic scale) for a dipole transmitter placed on the front (abdominal region) of a computational human body model without (radiative) and with (surface) the metamaterial textiles in FIG. 7A, according to embodiments of the present disclosure. The transmit power is the same in both configurations. The solid white lines show the power density contour line S = Sback where Sback is the power density at the location of receiver placed on the back of the body. [00148] Reference is now made to FIG. 11C, which is a schematic illustration of power density radiated in front of the body along the dotted white line in FIG. 11A, according to embodiments of the present disclosure. Solid line shows l/d $^{2}$fit, where d is the distance from the body. The distance in front of the body at which S = Sback is estimated to be 22.4 m. [00149] Data security is essential for the transmission of health and other personal data within body networks. Conventional wireless systems, however, are vulnerable to eavesdropping because