Control of Micro/Nano Bio-mimetic Structures for Fluidic Devices

流体装置微/纳米仿生结构的控制

• 批准号: 0624597
• 负责人: Santosh Devasia
• 金额: $ 34万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0624597&HistoricalAwards=false
• 关键词: Control; Micro; Nano; Bio; mimetic

The proposed work will study the optimal (minimal-energy) control of micro/nano bio-mimetic cilia for bio-fluidic devices. The goal is to achieve bio-compatible transport of small amounts of fluids without the need for cumbersome actuators such as external pumps used for fluid transport in current devices thereby, enable device portability. The novelty of the proposed work is that it will achieve this bio-compatible fluid transport by mimicking biological systems; in particular, the proposed design will use micro/nano-scale bio-mimetic cilia (similar to hair-like structures used in biological systems) for fluid transport. The key idea is to asymmetrically excite the bio-mimetic cilia array at frequencies close to vibrational resonance of the cilia. The asymmetry of the vibrations produces net fluid flow; and the closeness of the excitation frequency to the resonance frequency of the cilia array enables relatively large movements of the bio-mimetic cilia. The main control issue is to maximize the fluid flow with minimal input energy for device portability. The optimization of the distributed fluid-structure interactions arising from cilia array will use envelope-based flow prediction and sub-layer methods, along with nonlinear structural vibration modeling for: (a) modeling the nonlinear cilia dynamics; (b) quantifying the flow produced by the cilia array; and (c) optimizing the control input to maximize the resulting flow. To obtain the optimal control input, the proposed work will solve the simultaneous optimization of trajectory tracking and output transitions for maximizing the flow generated by the cilia while minimizing the input energy. The research will also investigate convergence of iterative algorithms proposed to solve this nonlinear optimization problem. In this sense, the proposed research will advance the state-of-the-art in optimal control of nonlinear systems. In addition to the theoretical effort, the control techniques will be implemented and evaluated experimentally; thus, the research will lay the groundwork for enabling such bio-mimetic cilia for fluidic devices.This research will enable the bio-compatible transport of small amounts of fluid samples in emerging applications such as disposable biofluidic chips. The goal is to enhance the portability of bio-devices by removing the need for cumbersome actuators such as external pumps used for fluid transport in current bio-fluidic devices. The proposed design will use micro/nano-scale bio-mimetic cilia for fluid transport. Biological cilia are hair-like structures whose rhythmic beating: (a) provides motility for cells and micro-organisms; and (b) moves fluids and particles in biological ducts. For example, cilia are used in the human body to sweep: (i) mucous in the respiratory system, and (ii) eggs toward the uterus. The proposed device will use vibration/acoustic to indirectly excite the bio-mimetic cilia, which will lead to a biocompatible actuation mechanism since it avoids damage of biosamples during fluid transport. Moreover, the relatively easy coupling between a piezo-actuator (to generate the vibration/acoustics) and the cilia will enable convenient fluid transport through remote actuation for disposable biofluidic chips. The outcome of this proposal will be a biomimetic device that will enable applications which need to: (a) control the diffusion rate of chemical reactions, (b) efficiently mix several different bio/chemical species, or (c) transport liquid in a controllable way. The proposed work will offer research and educational experience to undergraduate students and promote the involvement of minority students in research. Thus, it will help to build the research and human resource infrastructure needed in emerging biotechnology areas; this effort is in keeping with a recent NSF sponsored workshop finding that Mechanical Engineering Departments "should aggressively integrate biology and life sciences into the curriculum."

拟议的工作将研究生物流体设备的微/纳米仿生纤毛的最佳（最小能量）控制。 目标是实现少量流体的生物相容性输送，而不需要笨重的致动器，例如用于当前装置中的流体输送的外部泵，从而实现装置的便携性。拟议工作的新奇在于，它将通过模仿生物系统来实现这种生物相容的流体输送;特别是，拟议的设计将使用微/纳米级生物模拟纤毛（类似于生物系统中使用的毛发状结构）进行流体输送。 关键想法是以接近纤毛振动共振的频率不对称地激发仿生纤毛阵列。振动的不对称性产生净流体流动;并且激励频率与纤毛阵列的共振频率的接近使得仿生纤毛能够进行相对大的运动。主要的控制问题是以最小的输入能量使流体流量最大化，以实现装置的便携性。由纤毛阵列引起的分布式流体-结构相互作用的优化将使用基于微扰的流动预测和子层方法，沿着非线性结构振动建模，用于：（a）对非线性纤毛动力学建模;（B）量化由纤毛阵列产生的流动;以及（c）优化控制输入以使所得流动最大化。为了获得最佳控制输入，所提出的工作将解决轨迹跟踪和输出转换的同时优化，以最大化纤毛产生的流量，同时最小化输入能量。本研究亦将探讨此非线性最佳化问题之迭代演算法之收敛性。从这个意义上说，所提出的研究将推进非线性系统的最优控制的最新技术。除了理论上的努力，控制技术将实施和实验评估;因此，该研究将奠定基础，使这种仿生纤毛的流体设备。这项研究将使生物相容性运输的少量流体样品的新兴应用，如一次性生物流体芯片。目标是通过消除对笨重的致动器（诸如用于当前生物流体装置中的流体输送的外部泵）的需要来增强生物装置的便携性。所提出的设计将使用微/纳米级仿生纤毛进行流体输送。生物纤毛是毛发状结构，其有节奏的跳动：（a）为细胞和微生物提供运动性;（B）移动生物导管中的流体和颗粒。例如，纤毛在人体中用于清扫：（i）呼吸系统中的粘液，以及（ii）朝向子宫的卵。 所提出的装置将使用振动/声学来间接地激发仿生纤毛，这将导致生物相容性致动机制，因为它避免了流体输送期间生物样品的损坏。此外，压电致动器（以产生振动/声学）与纤毛之间的相对容易的耦合将使得能够通过用于一次性生物流体芯片的远程致动来方便地进行流体输送。该提议的结果将是一种仿生装置，该仿生装置将使需要以下的应用成为可能：（a）控制化学反应的扩散速率，（B）有效地混合几种不同的生物/化学物质，或（c）以可控的方式输送液体。拟议的工作将为本科生提供研究和教育经验，并促进少数民族学生参与研究。因此，它将有助于建立新兴生物技术领域所需的研究和人力资源基础设施;这一努力与NSF最近赞助的研讨会发现，机械工程系“应积极将生物学和生命科学纳入课程。"