Preparation of advanced functional materials from agricultural waste by eco-friendly processing route is inevitable for sustainable development. This work demonstrates the development of carbon/silica (C/SiO2) and carbon/silicon carbide (C/ SiC) composite foam monoliths of low thermal conductivity, high EMI shielding performance and reasonable compressive strength from rice husk. The C/SiO2 and C/SiC composite foams are obtained by carbonization and subsequent carbothermal reduction, respectively, of rice husk–sucrose composites consolidated by filter-pressing rice husk powder dispersed in sucrose solutions of various concentrations (300–600 g L− 1). The amorphous nature of silica in C/SiO2 and the presence of β-SiC in C/SiC are evidenced from XRD and TEM analysis. The compressive strength and thermal conductivity are depending on the foam density which is tailored by sucrose solution concentration. The compressive strength in the ranges of 0.32–1.67 and 0.19–1.19 MPa are observed for C/SiO2 and C/SiC foams, respectively, with density in the ranges of 0.26–0.37 and 0.18–0.29 g cm− 3. The C/SiO2 and C/SiC exhibited thermal conductivity in the ranges of 0.150–0.205 W m− 1 K− 1 and 0.165–0.431 W m− 1 K− 1, respectively. The C/SiO2 and C/SiC composite foams show absorption dominated EMI shielding effectiveness in the ranges of 18–38.5 dB and 20–43.7 dB, respectively. The inherent pore channels and corrugated surface structure in rice husk, electrically conducting carbon and dielectric SiO2 and SiC contribute to the total EMI shielding.

Biodegradable epoxy (B-epoxy) was prepared from diglycidyl ether of bisphenol A and epoxidized linseed oil. The mechanical properties of B-epoxy composites reinforced with multi-walled carbon nanotubes (MWCNTs/B-epoxy) were examined by employing dynamic mechanical analysis, critical stress intensity factor (KIC) tests, and impact strength tests. The electromagnetic interference shielding effectiveness (EMI-SE) of the composites was evaluated using reflection and absorption methods. Mechanical properties of MWCNTs/B-epoxy were enhanced with an increase in the MWCNT content, whereas they deteriorated when the MWCNT content was >5 parts per hundred resin (phr). This can likely be attributed to the entanglement of MWCNTs with each other in the B-epoxy due to the presence of an excess amount of MWCNTs. The highest EMI-SE obtained was ~16 dB for the MWCNTs/B-epoxy composites with a MWCNT content of 13 phr at 1.4 GHz. The composites (13 phr) exhibited the minimum EMI-SE (90%) when used as shielding materials at 1.4 GHz. The EMI-SE of the MWCNTs/B-epoxy also increased with an increase in the MWCNT content, which is a key factor affecting the EMI-SE.

The electromagnetic interference(EMI) shielding sheet of grid pattern for the wireless charger has been designed by using grid pattern metal sheet, PET & DST stacking and laminating technology. For this purpose, the twisting protection and the bubbling prevention device, the automatic position adjustment controller, the visual sensors and the motor actuator for controller, the EMI shielding sheet cutting device and the main control system have been developed for manufacturing the apparatus. As the study result, the development on manufacturing the equipment and shielding sheet of the EMI shielding sheet of grid pattern for the wireless charger having the lamination productivity of 27.4m/min exceeded the target of 8m/min in this study. In addition, the magnetic induction and the applicable shielding sheet were prepared in the magnetic resonance system, all of the two wireless charging system. The power with a band of average 6.87MHz of shielding sheet was greater than the target of 30dB to 32.57dB. The available frequency with a band of average 7.95MHz the target was exceeded by a 7.00MHz.

The purpose of this study was to develop a grid forming equipment of the electromagenetic interference(EMI) shielding sheet for use in a wireless charger. In addition, the present study was to form a lattice in the surface of the thin metal ribbon to exert an electromagnetic wave shielding performance of the precision small electronic devices such as smart phones. For this, grid forming presses such as manual pressurized press, automatic pressurized press, heat pressurized press, and continuous grid forming equipment with cylinder roll type, and a grid inspection and grid uniformity inspection devices have been developed. Finally, the cylindrical roller-type continuous grid forming equipment showed the best suited.

The grid pattern electromagnetic interference(EMI) shielding sheet for the wireless charger has been designed using grid pattern metal sheet, PET & DST stacking and laminating technology. Also, an automatic manufacturing system of the grid pattern EMI shielding sheet for the wireless charger is developed. This metal sheet with grid pattern is an effective shield against EMI that can not shield completely by existing single metal sheet. And the developed automatic manufacturing system having a laminated productivity exceeds the 8m/min can stack and lamination thin metal sheets without any wrinkles.

The EMI shield material with narrow width has some deficiencies in shielding capability and this deficiencies are caused by the inconsistent relationship between the inductance and temperature after heat treatment. This study is performed to develop a nano crystal magnetization heat treatment process technology and design a EMI shielding material with wide width up to 350mm. As a result, the performance of the developed wide EMI shield material satisfies all the objects of this study such as the inductance, thickness, permeability, ribbon productivity, lamination productivity. Also, we find that this wide EMI shield material can be used effectively for the EMI shield room, large medical equipment and so on.

Multi-layered metal sheet for electromagnetic interference(EMI) shielding purpose has been designed using metal sheet, PET & DST stacking and laminating technology. Also, an automatic manufacturing system is developed. This metal sheet with multi-layered structure is an effective shield against EMI that can not shield completely by single metal sheet. And the developed automatic manufacturing system can stack and lamination thin metal sheets without any wrinkles.

Ultra thin sheet for electromagnetic interference(EMI) shielding purpose has been designed using base metal, PET & DST sheet stacking technology. Also, an automatic manufacturing system is developed. This ultra thin EMI shielding sheet is an effective shield against low frequency(~300kHz) EMI that can not shield completely by the existing EMI shielding sheet. And the developed automatic manufacturing system can stack ultra thin shielding sheet without any wrinkles.