Design and Development of Carbon Nanofiber based Lightweight Flexible Nanocomposite Structure for EMI Shielding Application

Abstract

The present work deals with design and development of nanocomposite structure of carbon nanofiber CNF (5 to 20 wt%) encapsulated in polyurethane using the solution casting technique. CNF15 nanocomposite (15 wt% CNF in PU) having low density ~0.112g/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> shows the optimized value for conductivity and dielectric properties in the X-band of frequency. The total EMI shielding effectiveness (SET) of the CNF15 nanocomposite structure is above 30 dB covering the entire X-band with its maximum value of ~42.01 dB at 12.4 GHz at just 0.7 mm thick sample. The capacity to handle the complex environment and ability to work for conformal electronic devices is investigated by the measurement SET values after 1 hour of sonication in water, bending at direction and manually bending for 500 mechanical cycles. The EMI shielding mechanism is explained on the basis of dielectric properties and morphology of the fabricated nanocomposite structure, The SET is analyzed by performing the simulation using the CST microwave studio in 1–18 GHz to ensure the usage of fabricated structure for the wideband application. The high EMI shielding is achieved for the fabricated thin, flexible, nanocomposite structures, making them appropriate thin coating of conformal electronic devices in military and space applications.