Flexible silver nanorods/carbon fiber felt metacomposites with epsilon-near-zero property adjusted by compressive deformation

Epsilon-near-zero (ENZ) materials exhibit great potentials in the practical applications of sensors, electronic skin, and wearable devices, when they own the properties of flexibility and compression. In this work, the silver nanorods (AgNRs)/carbon fiber felt (CFF) composites with ENZ property from 1 kHz to 1 MHz were achieved by adjusting the content of AgNRs and the compressed elastic deformation. Positive permittivity was obtained from the composite of 2.5 wt% AgNRs without compressive deformation; however, the ENZ property with negative permittivity as small as about − 50 was realized from this composite with 50% compressive deformation. During the process of compressive deformation, the isolated AgNRs were easier to form a conductive network and brought about a lower percolation threshold, resulting in ENZ property. The electron density was enhanced with increasing compressive deformation, which was closely related to negative permittivity and the alternating current conductivity.