Liquid Metal@Reduced Graphene Oxide Composite Putty for Microwave Absorption

The development of radar technology has increased thepossibilityof warplanes being detected. Therefore, radar stealth capability iscritical for warplanes. Currently, microwave-absorbing materials withplasticity are urgently needed to reduce the strong electromagneticscattering from plenty of small gaps on aircraft. Here, we proposea strategy to encapsulate liquid metal with reduced graphene oxide(rGO) to form a plastic microwave-absorbing putty. The putty is formedby a self-assembly electrostatic method to create a sparse foam structurewith good plasticity. Interestingly, the nonmagnetic putty not onlyshows a dielectric loss but also exhibits unique magnetic losses.This synergistic mechanism allows the putty to obtain a minimum reflection(RLmin) of -58.86 dB at 8.93 GHz with a small thicknessof 3.57 mm. The excellent properties of this composite putty allowit to be a candidate for microwave-absorbing putties to reduce theradar cross section of airplanes.