In both experiment and simulation, we demonstrate a graded array of Helmholtz resonators (HRs) with cross-linked polypropylene (IXPP) ferroelectret films on the inner walls of cavities, which can realize both sound absorption and energy harvesting within 300–800 Hz. This dual-function graded array contains nine HRs with different sizes, which can offer a broadband working frequency and absorb part of acoustic energy. The unique ability of IXPP ferroelectret films can be used to efficiently harvest sound energy during resonant performances. An electric circuit is designed for collecting electrical signals of each branch individually. The average values of sound absorption coefficient and output power are about 0.81 and 1.43 nW in the range of 300–800 Hz with an input sound pressure level (SPL) of 100 dB in experiment, respectively. Our results enrich the fundamental techniques of both sound absorption and acoustic energy harvesting (AEH), which can pave a way for designing acoustic device in the field of sound absorption and energy conversion for future engineering application.

中文翻译：

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亥姆霍兹谐振器分级阵列的宽带吸声和能量收集


在实验和模拟中，我们展示了腔内壁上具有交联聚丙烯（IXPP）铁电驻极体薄膜的亥姆霍兹谐振器（HR）的分级阵列，它可以在300-800 Hz范围内实现吸声和能量收集。这种双功能渐变阵列包含九个不同尺寸的HR，可以​​提供宽带工作频率并吸收部分声能。 IXPP 铁电驻极体薄膜的独特能力可用于在谐振表演期间有效收集声能。电路被设计用于单独收集每个分支的电信号。实验中输入声压级（SPL）为100 dB时，吸声系数和输出功率的平均值在300-800 Hz范围内分别约为0.81和1.43 nW。我们的成果丰富了吸声和声能收集（AEH）的基础技术，为未来工程应用中吸声和能量转换领域的声学器件设计铺平了道路。