SENSORS: Collaborative Research: Artificial Cilia- Biologically Inspired Nanosensors

微小的毛发状传感器，或称纤毛，在检测包括人类在内的许多生物物种方面发挥着非常重要的作用。这项研究工作从内耳的耳蜗和纤毛的转导过程中获得灵感来设计声学传感器。具体地说，该项目建议使用磁致伸缩材料的纳米线作为超声波和声音信号的毛发传感器。与电流传感器相比，拟议的人造纤毛传感器(ACTS)具有许多优势，因为与目前的超声波压力检测器相比，这些“磁性毛发”可以很容易地制造成阵列，以提高灵敏度和/或空间分辨率，并且毛发的直径、长度和硬度可以根据广泛的频率范围进行定制。我们独特的磁致伸缩材料选择将使使用巨磁电阻(GMR)传感器同时检测多个纤毛的不同共振成为可能。随着传感器的发展，一些基本的科学概念将被作为这项工作的有价值的副产品进行研究，包括在纳米尺度上定制晶体结构和颗粒尺寸的过程，以获得比其宏观尺度对应的材料更具延展性和更大的传导性的材料，以及将通过声学共振测量来理解纳米尺度的杨氏模数。随着ACTS的发展导致能够区分具有约40 nm纤毛间距量级的空间分辨率的压力波，将实现对科学的独特贡献。其他未来的传感功能(除了超声波和声学信号)可能包括流体流动、压力变化、化学污染和/或磁场。这些参数可以通过分别测量声波共振(如在水听器阵列中)、声波共振室(如在耳朵的耳蜗处)、毛发运动、因吸附的化学物质引起的共振频率变化和毛发运动来感知。此外，未来的信号处理应该能够使用纳米阵列来检测频率、相位和方向性。此外，PI在让本科生参与实验室研究经验方面都有良好的记录，并将继续通过这个项目做到这一点，包括与摩根州立大学(HBCU)的新合作，为摩根州立大学土木工程本科学生提供暑期实习机会。这个项目的跨学科、跨机构的性质将使本科生和研究生接触到许多独特的机会。

Tiny hair-like sensors, or cilia, play a very important role in detection for many biological species, including humans. This research effort takes inspiration from the transduction processes of the inner ear's cochlea and cilia to design acoustic sensors. Specifically, this project proposes to use nanowires of magnetostrictive materials as hair-like sensors of ultrasonic and acoustic signals. The proposed Artificial Cilia Transducers (ACTs) have many advantages over current sensors, as these "magnetic hairs" can be easily fabricated in arrays for enhanced sensitivity and/or spatial resolution as compared to current ultrasonic pressure detectors, and the diameters, lengths and stiffnesses of the hairs can be tailored to a wide range of frequencies. Our unique choice of magnetostrictive materials will enable simultaneous detection of the distinct resonances of multiple cilia using giant magnetoresistive (GMR) sensors. Along with sensor development, several fundamental concepts of science will be investigated as valuable byproducts of this work, including processes for tailoring crystalline texture and grain size at the nanoscale for achieving materials that are more ductile and have larger transduction than their macroscaled counterparts and an understanding of Young's modulus at the nanoscale will be developed through acoustic resonance measurements.Unique contributions to science will be realized as the development of ACTs lead to the ability to discriminate pressure waves with spatial resolutions on the order of the inter-cilia spacing, ~ 40 nm. Other future sensing capabilities (beyond ultrasonic and acoustic signals) could include fluid flow, pressure variations, chemical contamination, and/or magnetic fields. These parameters can be sensed by measuring sonic resonance (as in hydrophone arrays), acoustic resonance chambers (as in the ear's cochlea), hair motion, changes in resonant frequencies due to adsorbed chemicals and hair motion, respectively. Also, future signal processing should enable the detection of frequency, phase, and directionality using nanoarrays. Additionally, the PIs all have strong track records for involving undergraduate students in laboratory research experiences and will continue to do so with this project, including a new collaboration with Morgan State University (an HBCU) that will provide summer internships for Morgan State undergraduate civil Engineering students. The interdisciplinary, inter-institutional nature of this project will be expose undergraduate and graduate students to many unique opportunities.