Design, Simulation, and Validation of a Flexible Liquid Metal Reconfigurable Metasurface

In this paper, a continuously reconfigurable metasurface based on liquid metal microfluidics is proposed, which achieves flexible device fabrication, reconfiguration response, and frequency-tunable performance. The designed metasurface unit consists of a double-C-shape, and its frequency can be continuously adjusted in the ranges of 3.7–5.72 and 6.73–7.94 GHz. According to the simulation, the resonance frequency of the metasurface is almost unchanged as the NaOH concentration increases, while the reflection amplitude first rises and then falls, and the power loss density at the resonant frequency increases. Moreover, the designed metasurface can achieve continuous regulation of resonant frequency and is beneficial to the attenuation of electromagnetic waves in the lower frequency, compared with solid metal metasurface. The subarray device is fabricated with flexible materials, liquid metal, and NaOH solution. Subsequently, the multi-directional microfluidics of liquid metal enable the continuous reconfiguration of the metasurface, and the state can be maintained when power is off. Finally, a 30 × 30 cm prototype is formed by assembling the subarrays. The experimental results of the frequency regulation response are consistent with the simulation results. This work presents a new method for the electromagnetic metasurface with continuously adjustable frequency, low power consumption, low cost, and flexible reconfiguration.