An acoustic rectifier
An acoustic rectifier
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声学整流器
DOI：
10.1038/nmat2881
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发表时间：
2010-12-01
期刊：
影响因子：
41.2
通讯作者：
Cheng, J. C.
中科院分区：
文献类型：
--
作者：
Liang, B.;Guo, X. S.;Cheng, J. C.
声信号的检测与一系列实际应用有关，例如在医疗诊断中。然而，虽然已经证明了电流和热通量等其他能量形式的整流(1-6)，但尚未实现声学整流。在“声波二极管”(7)理论的基础上，我们首次提出了声波整流能流的实验证明。将超晶格与超声造影剂微泡悬浮液相耦合，制成了一维声整流器。在两个频段内观察到了显著的整流效应，其位置与理论预测相符。在微泡悬浮液浓度优化后，精馏比可高达10(4)。这种声学整流器的实现应该具有很大的实际意义，例如在医学应用中的超声聚焦。
The detection of acoustic signals is of relevance for a range of practical applications, for example in medical diagnostics. However, whereas rectification of electric current and other energy forms such as thermal flux has been demonstrated(1-6), acoustic rectification has not yet been achieved. Here, on the basis of the earlier theoretical proposal of an 'acoustic diode'(7), we present the first experimental demonstration of a rectified energy flux of acoustic waves. A one-dimensional acoustic rectifier is fabricated by coupling a superlattice with a layer of ultrasound contrast agent microbubble suspension. A significant rectifying effect is observed within two frequency bands at locations that agree well with theoretical predictions. Following optimization of the concentration of the microbubble suspension, rectifying ratios can be as high as similar to 10(4). This realization of an acoustic rectifier should have substantial practical significance, for example in the focusing of ultrasound in medical applications.