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Bar-Cohen : Biomimetics: Biologically Inspired Technologies DK3163_c012 Final Proof page 315 21.9.2005 11:54pm

Multifunctional Materials 315

VES
CEQ
3 4

turn-on at 10.9 GHz turn-on at 11.9 GHz
0 0
Dielectric constant Simulation Dielectric constant Simulation

Theoretical continuation
Measurement- 2 layers
−3 Measurement- 2 layers Theoretical continuation
Measurement- 3 layers −4
Measurement- 3 layers

−6
−8
4 6 8 10 12 14 16 18 6 8 10 12 14 16 18
(a) Frequency (GHz) (b) Frequency (GHz)

EG-3 EG-2
5
4

turn-on at 10.1 GHz turn-on at 9.5 GHz
0 0
Dielectric constant Simulation Dielectric constant Simulation

Theoretical continuation
Theoretical continuation
Measurement- 1 layer(b)
−4 Measurement- 1 layer(a) −5 Measurement- 1 layer
Measurement- 2 layers
Measurement- 2 layers
Measurement- 3 layers Measurement- 3 layers

−8 −10
6 8 10 12 14 16 18 4 6 8 10 12 14 16 18
(c) Frequency (GHz) (d) Frequency (GHz)
Figure 12.4 Numerical and experimental characterization of the thin-wire EM composite samples. Data for panels
made of the same host composite material and wire diameter are displayed in one chart since their numerical
simulations are identical. ‘‘Turn-on’’ indicates the transition between the stop-band and pass-band, or the frequency
above which the material transmits electromagnetic radiation. (a) 50 mm (0.002 in.) diameter wires embedded in
cyanate ester/quartz composite. (b) 50 mm diameter wires embedded in vinyl ester/Spectra composite. (c) 75 mm
(0.003 in.) diameter wires embedded in epoxy/E-glass composite (two single layer samples were manufactured
and measured for this case). (d) 50 mm diameter wires embedded in epoxy/E-glass composite.

carriers with a wire carrier. A comprehensive description of the textile braiding process is given by
Ko et al. (1989) and Ko (2001). Modeling of the mechanical properties has also been developed for
textile braids (see e.g., Cox et al., 1994; Naik, 1995; Xu et al., 1995; McGlockton et al., 2003; Yang
et al., 2003).
Braiding wire with the reinforcing fibers results in an electromagnetic element with uniform
geometry that maintains its shape under considerable handling and other processing conditions. The