Hydrogel microphones for stealthy underwater listening.
Hydrogel microphones for stealthy underwater listening.
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用于水下隐形聆听的水凝胶麦克风
DOI：
10.1038/ncomms12316
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发表时间：
2016-08-24
影响因子：
16.6
通讯作者：
Tan L
中科院分区：
文献类型：
--
作者：
Gao Y;Song J;Li S;Elowsky C;Zhou Y;Ducharme S;Chen YM;Zhou Q;Tan L
探索海洋中丰富的资源需要水下声学探测器，其具有高灵敏度接收来自更远距离的低频声音和零反射的能力。在这里，我们通过在水凝胶基质中集成易于变形的金属纳米颗粒网络来解决这两个挑战，以用作无腔麦克风。由于金属纳米颗粒可以密集地植入夹杂物中，甚至可以排列成相干阵列，因此该麦克风可以检测不同角度的静态负载和微风，以及幅度低至4 Pa的20 Hz至3 kHz的水声信号。与通过在厚度方向上使器件变形来响应刺激的介电电容器或基于腔体的麦克风不同，这种水凝胶器件通过双电层的瞬态调制来响应，从而在不使用任何信号放大工具的情况下产生非凡的灵敏度（217 nF kPa−1或24 μC N−1，偏压为1.0 V）。 传统的陶瓷声纳遭受与水的大的声阻抗失配，使它们容易被检测到。在这里，Gao等人报告了一种使用填充有刺激响应金属纳米颗粒的水凝胶的新设计，该水凝胶以高灵敏度和零反射检测低频声音。
Exploring the abundant resources in the ocean requires underwater acoustic detectors with a high-sensitivity reception of low-frequency sound from greater distances and zero reflections. Here we address both challenges by integrating an easily deformable network of metal nanoparticles in a hydrogel matrix for use as a cavity-free microphone. Since metal nanoparticles can be densely implanted as inclusions, and can even be arranged in coherent arrays, this microphone can detect static loads and air breezes from different angles, as well as underwater acoustic signals from 20 Hz to 3 kHz at amplitudes as low as 4 Pa. Unlike dielectric capacitors or cavity-based microphones that respond to stimuli by deforming the device in thickness directions, this hydrogel device responds with a transient modulation of electric double layers, resulting in an extraordinary sensitivity (217 nF kPa−1 or 24 μC N−1 at a bias of 1.0 V) without using any signal amplification tools. Conventional ceramic SONAR suffers from large acoustic impedance mismatch with water, rendering them easily detectable. Here, Gao et al. report a new design using a hydrogel filled with stimuli-responsive metal nanoparticles, which detects low-frequency sound with a high-sensitivity and zero-reflection.