## 3 Results and Discussion
### Shielding Properties of Embedded Cu Meshes  
The phenomenon of shielding electromagnetic radiation by a material is based on the processes of reflection, absorption and dissipation of the energy of an electromagnetic wave (EMW) in a material. A quantitative assessment of the shielding efficiency is the shielding coefficient \(SE\), determined by (5) (dB). \[SE=20\lg\frac{E_{1}}{E_{2}} \tag{5}\]  
where \(E_{1}\) is the EMW amplitude at an arbitrary point of the shielding space without the screen and \(E_{2}\) is the EMW amplitude at the same point with the screen. Concerning the material, the shielding coefficient can be interpreted as a value opposite in sign to the generally accepted transmission coefficient \(T\) (dB) (6):  
\[SE=-T \tag{6}\]  
The main shielding mechanisms are absorption (\(A\)) and reflection (\(R\)); according to the law of conservation of energy, these coefficients are related by the relation \(A+R+T=1\)[46]. The absorption mechanism as the main shielding mechanism is fully characteristic of graphene [47]. Single-walled carbon nanotubes [48], conducting polymers [49] and Ag  
Figure 11: Photo e-LCM 180 in bend state (a); Bending stability of Cu meshes and embedded Cu meshes (b). Figure 10: Example of obtaining electrically conductive scotch tape based on SCM 180.  
nanowires [50] have a mixed shielding mechanism (absorption and reflection in different proportions), and with a decrease in sheet resistance, the shielding mechanism shifts towards reflection. For micro and nanomesh conductive coatings with low sheet resistance, which include the copper mesh offered by us, reflection is the main shielding mechanism. More than 80-90% of all incident radiation is reflected [51]. A decrease in the specific surface resistance leads to an increase in the fraction of reflected radiation up to 99% [23]. Figure 12 shows the spectral dependences of the \(SE\) parameter for the e-LCM (Figure 12a) and e-SCM (Figure 12b). The graphs clearly show the relationship between sheet resistance and \(SE\) value. Electroplating copper on Cu seed meshes leads to an intense increase in \(SE\). Thus, for e-LCM (Figure 12a), an increase in the electroplating time leads to a significant increase in \(SE\), from 10.17 dB to 37.41 dB (for 30 s) and 58.75 dB (180 s) at 10 MHz. For e-SCM (Figure 12b), there is a significant increase in \(SE\), from 15.12 dB to 48.96 dB (for 30 s) and 65.03 dB (180 s) at 10 MHz. Figure 12a,b shows the following: for e-LCM 0 and e-SCM 0 there is no frequency dependence in the studied range. An increase in the electroplating time leads to an intense increase in \(SE\), due to a decrease in sheet resistance. In addition, the frequency dependence of \(SE\) becomes more pronounced. Thus, for e-LCM 30 the \(SE\) difference at the boundaries of the range is 9.1 dB, while for e-SCM this value is 6.44 dB. A further decrease in sheet resistance gives an even more significant difference. For the e-LCM 180 the \(SE\) difference is 23.26 dB; for the e-SCM 180 the \(SE\) difference is 18.88 dB. The average cell size makes a significant contribution to the frequency dependence of \(SE\). The frequency dependence of \(SE\) is more pronounced for e-LCM, consistent with modern concepts of shielding electromagnetic radiation by perforated films. According to the continuous layer model [33], which describes the relationship between sheet resistance and \(SE\) by the Equation (7). \[SE=20\lg\biggl{(}1+\frac{Z_{0}}{2R_{s}}\biggr{)} \tag{7}\]  
Figure 12: \(SE\) parameter for e-LCM (**a**) and e-SCM (**b**); Comparison of the \(SE\) parameter for e-LCM and e-SCM at frequencies of 100 MHz and 1 GHz with a continuous layer model (**c**). where \(R_{\rm{s}}\) is the sheet resistance, \(Z_{0}\) = 377 \(\Omega\) is the wave impedance of free space. At frequencies less than 100 MHz, agreement with the continuous layer model is quite good (Figure 12c).