Phase 2 - optical readout of novel directional MEMS microphone technology

新兴的语音应用，如自动语音识别，正在推动对定向**麦克风的需求，这种麦克风可以从特定方向拾取声音，同时不受其他**来源的环境噪声的影响。目前的定向声音捕获解决方案基本上依赖于三角测量：**全向麦克风的空间阵列通过测量多个阵列**元素之间的时间延迟来实现方向灵敏度。这些阵列大得令人不便，而且只在声波**波长(低频为10米)小于阵列尺寸的频率上定向。**Soundskritt正在根据基础声学研究的最新进展**开发一种新型的小型化定向芯片麦克风。它们使用非常柔软的纳米纤维，这样**它们就可以随着声压波的强度--最重要的--方向移动。然而，**这些纳米纤维的极度柔软使得测量它们的位移(即记录声音)非常**具有挑战性。极度柔软使光纤与传统的电位移测量传感器**不兼容，例如电应变仪(这会增加光纤不可接受的重量)或**电容式读数(这会产生比**声波施加的力大得多的寄生静电力)。**Soundskritt正在研究两种不同的方法来解决这个限制：磁力(由**Soundskritt领导)和光学读数(由渥太华大学ST-Gelais实验室领导)。我们预计光学方法将产生**最高的性能(对于大多数微系统表征技术而言)，但将是最难**小型化的。我们的目标或我们的合作是同时开发这两种方法，并对它们进行**比较，以找到最有希望的一种。

Emerging voice applications, such as automatic speech recognition, are driving the need for directional**microphones that can pick up sound from a specific direction while being immune to ambient noise from other**sources. Current solutions for directional sound capture essentially rely on triangulation: a spatial array of**omnidirectional microphones achieves directional sensitivity by measuring time delay between multiple array**elements. These arrays are inconveniently large and are only directional at frequencies for which the acoustic**wavelength (>10 meters at low frequencies) is smaller than the array dimension.**Soundskrit is developing a new type of miniaturized directional on-chip microphone based on recent**progress emerging from fundamental acoustic research. They use nanofibers that are extremely soft, such that**they can move following the intensity and-most importantly-the direction of acoustic pressure waves. However,**the extreme softness of these nanofibers makes measuring their displacement (i.e., recording sound) extremely**challenging. Extreme softness makes the fiber incompatible with conventional electrical displacement**measurement transducers such as electrical strain gauges (which would add unacceptable weight to the fiber) or**capacitive readouts (which would create a parasitic electrostatic force much greater than the force exerted by**acoustic waves).**Soundskrit is investigating two different approaches for solving this limitation: magnetic (lead by**Soundskrit) and optical readouts (lead by St-Gelais lab at uOttawa). We expect the optical approach to yield the**highest performance (as for most microsystems characterization techniques), but to be the hardest to**miniaturize. The goal or our collaboration is to develop both approaches in parallel and to benchmark them**against one another to find the most promising one.