Collaborative Research: Actively Controllable Microfluidics with Film-Confined Redox-Magnetohydrodynamics: experiment and simulation

将研究小体积氧化还原聚合物修饰电极在磁场中的选择性活化，以控制微流体的空间和时间。这种新形式的磁流体动力学（MHD），与向溶液中添加氧化还原物质或根本不添加它们相反，克服了阻碍MHD在芯片实验室（LOAC）设备中使用的问题。它可以在更低的电压下实现更高的电流，从而实现更高的MHD力和更快的速度，而不会形成气泡或腐蚀，更快的响应时间，并且与探测器和样品兼容。与其他微型泵相比，MHD具有更大的通用性，因为流量可以在不重新设计设备通道的情况下进行编程。阿肯色大学化学与生物化学和密苏里科技大学机械与航空航天工程专业的研究人员将进行跨学科的合作研究。智力优势：限制在电极上的聚合物薄膜上的化学物质的还原/氧化在溶液中产生离子电流。当与磁场成直角时，产生的MHD力使流体在三维空间中流动。可单独寻址的电极将被制作成所需的图案，聚合物薄膜将被聚合并通过电化学表征，电极将被磁场中的电流和电压激活，流动将被溶液中的微珠运动监测。目标是(1)建立电极上氧化还原聚合物膜的大库仑容量、快速响应和等效电路模型；(2)使用垂直于磁场的氧化还原聚合物修饰电极的同心盘环结构控制和最大化流速、调整剖面、切换方向和驱动相邻逆流；(3)通过对氧化还原聚合物膜进行充电来维持流体流动；(4)通过模拟获得离子电流密度的空间图。MHD力密度和流体速度作为时间的函数，与实验进行比较，并评估超出实验限制的参数，以便更好地设计redox-MHD微流体装置。更广泛的影响：目标是以可编程的方式控制微流体，对公众感兴趣的产品产生深远的影响，例如用于医疗，环境和家庭用途的手持式，独立的化学分析单元。该项目的跨学科性质加强了参与研究的学生的训练。完成的软件模块将免费提供给科学界进行测试和进一步评估。新学院的科学、数学和语言艺术教师与亚利桑那大学和密苏里大学的导师之间的合作将以MHD为起点，激发中学生对力和能源主题的病毒式学习。学生们将与老师和导师合作进行自我指导的项目，用他们自己的词汇和观点通过视频交流结果，这些视频是他们编写、编辑、制作的，并发布在互联网上供公众观看和评论。这种方法有望弥合大学研究与中学教育之间的差距，同时加强STEM教育和教育工作者的发展，提高公众的科学素养和公众对科学技术的参与。

Fritch/Isaac1336853/1336722Selective activation of redox-polymer-modified electrodes in a small volume in magnetic fields will be investigated to control microfluidics spatially and temporally. This new form of magnetohydrodynamics (MHD), as opposed to adding redox species to the solution or not adding them at all, defeats problems that hinder MHD from use in lab-on-a-chip (LOAC) devices. It allows higher currents with lower voltages, and thus, higher MHD forces and faster velocities without bubble formation or corrosion, faster response times, and compatibility with detectors and samples. MHD offers greater versatility over other micropumps, because flow can be programmed without redesigning channels of a device. An interdisciplinary, preexisting collaboration of investigators in Chemistry & Biochemistry at the Univ. of Arkansas and in Mechanical & Aerospace Engineering at Missouri Univ. of Science & Technology will perform the research.Intellectual Merit :Reduction/oxidation of chemical species confined to polymer films on electrodes creates an ionic current in solution. When at right angles to the magnetic field, the resulting MHD force causes fluid to flow there in the third dimension. Individually-addressable electrodes will be fabricated in desired patterns, polymer films will be polymerized and characterized by electrochemistry, electrodes will be activated with current and voltage in magnetic fields, and flow will be monitored by microbead movement in solution. The objectives are to (1) establish large coulombic capacity, fast response, and equivalent circuit models for redox-polymer films on electrodes, (2) control and maximize flow velocities, tune profiles, switch direction, and drive adjacent counter-flows using concentric disk-ring configurations of redox-polymer-modified electrodes perpendicular to a magnetic field, (3) sustain fluid flow by recharging redox-polymer films, and (4) use simulations to obtain spatial maps of ionic current density, MHD force density, and fluid velocities as a function of time, compare with experiment, and evaluate parameters that exceed experimental limits to better design redox-MHD microfluidic devices.Broader Impacts :The goal is to control microfluidics in a programmable way with far-reaching consequences toward products of interest to the public, such as hand-held, self-contained chemical analysis units for medical, environmental, and household uses. The interdisciplinary nature of the project enhances training of students involved in the research. Completed software modules will become available for testing and further evaluation to the scientific community free of charge. An outreach collaboration between science, math, and language arts teachers at The New School and mentors at the U of A and Missouri S&T will use MHD as a starting point to stimulate viral learning for middle school students on topics of forces and energy. Students will perform self-directed projects in collaboration with teachers and mentors, communicate results with videos using their own vocabulary and perspective, which they have scripted, edited, produced, and post them on the internet for public viewing and commentary. This approach is expected to bridge the gap between university research and middle school education, while simultaneously enhancing STEM education and educator development and increasing public scientific literacy and public engagement with science and technology.