Fluid-Structure Interaction in Arthropod Mechanoreceptors with Application to Bio-Inspired Micro-Fluidic Sensors

在许多工程应用中，使用小传感器（1 mm或更小）识别微流特性的能力变得越来越重要。 在生物医学工程中，需要测量血管中的局部流动特性，因为这些流体特性对血管壁的结构完整性具有潜在影响。在航空航天工程中，正在开发用于许多应用的微平面，但是这些微平面的性能由于难以防止沿机翼沿着的流动分离和由此产生的失速而受到限制。在微型飞机飞行时测量这些特性被证明是一个重大挑战。 虽然工程师们几十年来一直在努力设计微流量传感器，但蟋蟀和其他节肢动物已经使用了几百万年的进化来开发微流量传感器，这些传感器对于威胁检测，捕食者躲避和通信至关重要。在常见的蟋蟀中，微流量传感器是两个天线状的附属物，称为尾索，位于腹部后部。每个尾椎上覆盖着大约800根丝状的机械感觉毛，每根都连接到一个产生尖峰的神经元。气流使毛发偏转，会改变毛发根部相关受体神经元的尖峰活动。 实验结果表明，该系统对热噪声引起的空气运动具有很高的灵敏度和探测能力。这种灵敏度超出了当前人工微流量传感器的能力。 我们的项目是基于这样的假设，即更好地了解节肢动物微流量传感器可以指导人工微流量传感器的开发和改进。 我们将发展新的建模和计算工具的非定常Stokes方程的基础上浸入边界技术，研究蟋蟀的cercal微传感器。这些模型将直接应用于人工微流量传感器。多年来，人们已经认识到，工程设计可以大大受益于对生物结构的理解。进化已经导致了非常复杂的解决方案，用于检测和分析动物周围环境中非常小的空气和流体运动的复杂问题，这些生物解决方案的各个方面原则上应该直接适用于或可推广到工程系统。 一个由工程师、数学家和神经生物学家组成的跨学科团队将开发新的建模和计算工具，以研究蟋蟀cercal微流量传感器的性能特征。两个主要的结果将直接适用于人工微流量传感器的设计。第一个成果将是一系列计算技术和模型，明确解决流体运动对传感器的影响。第二个成果将是一套生物学原理，这些原理是根据结构-流体相互作用的物理学约束而进化的，可以指导人工流量传感器的发展。

The ability to identify micro-flow characteristics using small sensors (1 mm or less) is becoming increasingly important in many engineering applications. In biomedical engineering there is a need to measure local flow properties in blood vessels because these fluid properties have a potential impact on the structural integrity of the vessel wall. In aerospace engineering, micro-planes are being developed for a number of applications, but the performance of these micro-planes is limited due to the difficulties of preventing flow separation along the wings and the resulting stall. Measuring these characteristics while the micro-plane is in flight is proving to be a significant challenge. While engineers have been grappling with the design of micro-flow-sensors for a few decades, crickets and other arthropods have used a few million years of evolution to develop micro-flow-sensors that are essential for threat detection, predator avoidance, and communication. In the common house cricket the micro-flow-sensors are two antenna-like appendages, called cerci, at the rear of the abdomen. Each cercus is covered with approximately 800 filiform mechanosensory hairs, each of which is connected to a single spike-generating neuron. Deflection of a hair by air currents changes the spiking activity of the associated receptor neuron at the base of the hair. It has been shown that the cercal system is extraordinarily sensitive and capable of detection of air motion caused by thermal noise. This sensitivity is beyond the capability of current artificial micro-flow sensors. Our project is based on the hypothesis that a better understanding of the arthropod micro-flow-sensor can guide the development and improvement of artificial micro-flow-sensors. We will develop new modeling and computational tools for the unsteady Stokes equations based on immersed boundary techniques to study the cercal micro-sensor in crickets. These models will be directly applicable to artificial micro-flow sensors.It has been recognized for many years that engineering design can greatly benefit from the understanding of biological structures. Evolution has resulted in very sophisticated solutions for complex problems related to the detection and analysis of very small air and fluid movements in an animal's immediate environment, and aspects of those biological solutions should be directly applicable or generalizable, in principle, for engineered systems. An interdisciplinary team that combines an engineer, mathematician and a neurobiologist will develop new modeling and computational tools to study performance characteristics of the cercal micro-flow sensor in crickets. Two principal outcomes will be directly applicable to design of artificial micro-flow sensors. The first outcome will be a collection of computational techniques and models which explicitly address the effect of fluid motion on the sensors. The second outcome will be a set of biological principles that evolved in response to constrains posed by the physics of structure-fluid interactions, and that can guide the development of artificial flow sensors.