Electromagnetic absorption/reflection manipulation by piezoelectric effect in PDMS/CZS/SWCNT/iron fabric hybrid composite

Abstract

The development of externally controlled electromagnetic shielding materials for protecting high-end electronic devices operating in GHz frequencies in satellite, military, and other communication fields is a significant technological challenge. Previously developed foamed composites and capacitor-based shielding materials exhibit active modulation of reflection and absorption. However, the higher thickness of foamed composites and the costly complex manufacture process along with requirement of an external voltage source by capacitor-based shields constrain their direct usability in realistic electronic applications. Herein, a piezo-tuned polydimethylsiloxane (PDMS)/carbon-doped zinc stannate (CZS)/single wall carbon nanotube (SWCNT)/iron fabric-based hybrid composite is prepared which features piezo-voltage controlled shielding performance. In this composite, the electrostatic modification of iron fabric electrodes and PDMS/CZS, PDMS/SWCNT layers by piezo-voltage enables control of dynamic reflection/absorption ability of 14.5–20 GHz electromagnetic radiation (EMR). Additionally, this composite reveals a functional transition from EMR reflector to EMR absorber at higher than 14 mV piezo-voltage. At 14.5 GHz frequency, this piezo-composite (1.51 mm thick) attains an excellent total shielding (SET) performance of 87.8 dB along with >98 % EMR absorption capability at 30.6 kPa pressure tuned 243 mV piezo-voltage. Hence, this achievement not only reveals the strategies for developing shielding materials for the future of electronic applications but also boosts the advancement of self-adaptable electromagnetic shielding.