We report the experimental demonstration of a voltage-tunable acoustic metasheet device with two highly asymmetric surfaces, made by combining two decorated membrane resonators (DMRs) separated by a sealed air column. The front surface of the metasheet is impedance matched to air and perfectly absorbing, while the back surface is hard and totally reflecting. When a suitable DC voltage is applied to the back side of the DMR via proper electrodes, the back surface of the metasheet can be tuned to impedance matched to air and perfectly absorbing, while the front surface is totally reflecting. The metasheet also exhibits high transmission contrast around two frequencies. The tunability of the reflection is over 23 dB at 388 Hz and that of the transmission is over 33 dB at 240 Hz and 590 Hz with 600 V of applied voltage.

中文翻译：

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具有高度不对称表面的电压可调声学元片

我们报告了具有两个高度不对称表面的电压可调声学元片器件的实验演示，该器件通过组合由密封气柱隔开的两个装饰膜谐振器 (DMR) 制成。超薄板的前表面与空气阻抗匹配并完全吸收，而后表面坚硬且完全反射。当通过适当的电极将合适的直流电压施加到 DMR 的背面时，可以将元片的背面调整为与空气阻抗匹配并完全吸收，而正面则完全反射。元片还表现出围绕两个频率的高透射对比度。反射的可调性在 388 Hz 时超过 23 dB，传输的可调性在 240 Hz 和 590 Hz 时超过 33 dB，施加电压为 600 V。