Carbon Nanotube/Polyolefin Elastomer Metacomposites with Adjustable Radio‐Frequency Negative Permittivity and Negative Permeability

Abstract Metacomposites have received significant interest over the past decade due to their unique double‐negative electromagnetic properties. Magnetic particles, conductive polymer, and carbon materials are the usual materals used to fabricate metamaterials with doube‐negative electromagnetic properties. Here, insulating polymer polyolefin elastomer is instead used as the matrix to construct such metacomposites. The composites are fabricated by using a swelling, bonding, and hot pressing process. Metacomposites in which 50 vol% binder and 3 vol%, 6 vol%, and 12 vol% multi‐walled carbon nanotubes are added show negative permittivity and permeability in the microwave frequency range. Additionally, the electromagnetic properties of the metacomposites can be effectively adjusted by changing the amount of binder and filler. Specifically, the distribution of carbon nanotubes in the matrix can be tuned and thus some composites can exhibit double‐negative properties after the hot pressing process, which indicates hot pressing is also an effective way to adjust electromagnetic performance. The first insulating‐polymer‐based double‐negative metamaterial is fabricated and new methods are examined to adjust its electromagnetic properties, which greatly expands the potential applications of metacomposites.