INVESTIGATIONS INTO ACTIVE BIOLOGICAL CELLULAR SENSOR ARRAYS AS INSPIRATON FOR ENGINEERED NONLINEAR SENSORS

对于动物来说，能够听到环境中的声音为它们打开了一个新世界；一种感知周围环境的新方法。许多动物已经进化到用声音来探测猎物和捕食者，寻找和追求潜在的伴侣，用回声定位“看”世界，并达到一定程度的复杂程度，使语言成为可能。在许多情况下，拥有敏锐的听觉真的是生死攸关的问题。不出所料，探测朋友和敌人发出的声音的重要性推动了声学传感器的进化。当我们听到针落地的声音时，我们会这样做，因为在很久以前，这种能力本可以挽救我们的生命。在人类、哺乳动物和昆虫等动物中，这种灵敏度已经达到了这样的程度：一些动物可以探测到在某些方面只能与噪音区别开来的声音——从热震动的角度来看，每个传感器最终都受到限制。为了达到这个目的，动物进化出了许多技巧来增强听觉能力。哺乳动物和昆虫使用充满分子马达的传感器，消耗能量来放大进入耳朵的微弱声音。这种反馈还使传感器能够选择性地过滤信号；改变它们敏感的频率范围。在这方面，生物声学传感器可以完美地适应动物的需求：锁定来自理想伴侣的声音，或者在眼睛不够的情况下形成它们世界的图像。尤其是昆虫，它们拥有各种灵敏的传感器。例如，蚊子使用一根从头部向空中伸出的刷子状天线，当有声音时，它就会振动。在这个天线的底部有大约16000个神经元（既能感知力又能产生力），这真是一个了不起的数字。为什么需要这么多？奇怪的是，有这么多神经元感知并反馈给天线一个力，一些非常复杂的动态行为就会发生。声音可以被放大，频率可以被接受或拒绝，信号可以被“锁定”以放大源。这个项目的灵感来自于这些传感器。我们能从蚊子等昆虫处理声音的方式中学到什么吗？我们能否利用它们的能力来制造新的传感器和驱动器，让它们能像它们一样听到声音？在这项研究的过程中，我们将研究细胞束的运作方式，以实现其精致的灵敏度。当一个传感器由相对简单的组件组成，但其行为超过其各部分的总和时，会发生什么？我们将对昆虫神经元的活动进行成像，并对它们如何共同工作提出假设。我们的目标是继续寻找在实际工程传感器中实现其特性的方法。工业上和其他科学领域中使用的许多换能器实际上是许多传感器和执行器的阵列，它们耦合在一起。通过了解蚊子等动物细胞阵列的机制，我们的目标是在真实系统中达到昆虫听觉的复杂程度、灵敏度和功能性。这些受生物启发的传感器有潜力改善声学传感器和致动器的工业应用，从医学超声成像，材料的无损检测，甚至机器人引导。

For animals, being able to listen to sounds in the environment opens up a new world; a new way to sense their surroundings. Many animals have evolved to use sound for detecting prey and predators, finding and courting with potential mates, 'seeing' the world with echolocation, and reaching a level of complexity to enable speech. In many cases, having an acute auditory sense can really be a matter of life and death. Unsurprisingly, the importance of detecting the sounds emitted by friends and foe has driven the evolution of remarkable acoustic sensors. When we can hear a pin drop, we do so because that ability, a long time ago, could have saved our lives. This level of sensitivity, in humans, mammals, and insects among others has reached a point where some animals can detect sound that is in some respects only just distinguishable from noise - from the thermal buffeting to which every sensor is ultimately restricted. In order to achieve this, animals have evolved many tricks to enhance their auditory capability. Mammals and insects use sensors full of molecular motors, consuming energy to provide amplification of weak sounds that enter their ears. This feedback also gives a sensor the ability to selectively filter signals; to change the range of frequencies to which they are sensitive. In this regard, a biological acoustic sensor can be adapted perfectly to the animal's needs: to lock into the sound from a desirable mate or to form an image of their world when eyes are not enough. Insects in particular employ a wide range of exquisite sensors. For example, the mosquito uses a brush-like antenna projected away from its head into the air, which oscillates when sound is present. At the base of this antenna is some 16000 neurones (that can both sense and generate force), a truly remarkable number. Why the need for so many? Strangely enough, with so many neurones sensing and feeding back a force to the antenna, some very complex dynamic behaviour can occur. Sound can be amplified, frequencies accepted or rejected, and signals can be 'locked' to zoom in on the source.This project is inspired by these sensors. Can we learn from the way insects like the mosquito process sound? Can we harness their ability to make new sensors and actuators that can hear like they do? Over the course of this fellowship, we will investigate the way in which bundles of cells operate to achieve their exquisite sensitivity. What happens when a sensor is composed of relatively simple components, but behaves more than the sum of its parts? We will image the activity of neurones in insects and develop hypotheses on how they work collectively. We aim to proceed by searching for ways in which to implement their properties in real engineered sensors. Many transducers used industrially, and in other scientific fields, are in fact arrays of many sensors and actuators, coupled together. By knowing the mechanisms of cellular arrays in animals such as the mosquito, we will aim to achieve the level of sophistication, sensitivity and functionality of insect hearing in real systems. These bio-inspired sensors have the potential to improve the industrial use of acoustic sensors and actuators, from medical ultrasound imaging, non-destructive testing of materials, and even robot guidance.