Collaborative Research: Magnetically Actuated Black Silicon Ratchet Surfaces for Digital Microfluidics

合作研究：用于数字微流体的磁驱动黑硅棘轮表面

• 批准号: 1951051
• 负责人: Sung Cho
• 金额: $ 31.02万
• 依托单位: University of Pittsburgh
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2024-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1951051&HistoricalAwards=false
• 关键词: Collaborative; Research; Magnetically; Actuated; Black

Since most of the sensitive and standardized bio-analytical techniques work in the liquid medium, the lab-on-a-chip system should be able to efficiently handle liquid solutions in micro/nano scale. To date, most of these systems have been developed based on the continuous flow system which lacks device reconfigurability. Consequently, much attention has been drawn to droplet-based lab-on-a-chip systems, namely, digital micro fluidic systems based on electrowetting that manipulate discrete liquid droplets rather than continuous liquid streams. Nevertheless, the electrowetting-based approach suffers from limitations such as high voltage requirement and biofouling, hampering many real applications. This project provides a straightforward pathway to a new digital micro fluidic platform without electrowetting-related limitations. The proposed platform exploits a purely mechanical means to drive discrete liquid droplets in a rapid, flexible, programmable, and reconfigurable manner. This project will also generate information and demonstration materials that can be directly used to promote both classroom teaching and general public's interest in materials, microfluidics, interfacial science, micro/nanotechnology. The project aims to explore the dynamically tunable surface morphology and consequential interfacial wettability using a black silicon ratchet surface in order to seek a new strategy to manipulate liquid droplets for the advancement of digital microfluidics. The proposed ratchet surface involves superhydrophobic black silicon scales on elastomer micropillars such that individual signals actuate individual scales and change the entire surface morphology forming a black silicon ratchet surface that drives liquid droplets. Consequently, droplets are essentially driven mechanically, not electrically. In addition, it is expected that conical nanostructures on the black silicon surface and/or slippery liquid infused porous surfaces to be integrated will significantly reduce biofouling. The proposed approach cannot be realized without elucidating underlying principles and establishing necessary techniques. Two principal investigators’ expertise encompassing mechanics, materials, manufacturing and microfluidics will be combined in order to achieve those understanding and knowledge, and finally open up a new interdisciplinary research area across smart composite materials and digital microfluidics. During the project, three objectives will be systematically pursued to towards the project goal. First, the mechanical characteristics involved in the proposed superhydrophobic ratchet surface will examined, Second, the interaction between liquid droplets and the superhydrophobic ratchet surface will be characterized and associated forces to manipulate liquid droplets on it will be investigated. Finally, droplet manipulations including droplet transporting, merging, and splitting along with the reduced biofouling will be demonstrated.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

由于大多数敏感和标准化的生物分析技术在液体培养基中起作用，因此实验室芯片系统应该能够以微/纳米尺度有效处理液体溶液。迄今为止，大多数这些系统都是基于缺乏设备可重构性的连续流系统开发的。因此，已经对基于液滴的实验室芯片系统引起了很多关注，即基于电子操纵的数字微流体系统，这些系统会操纵离散的液滴而不是连续的液体流。然而，基于电子的方法遭受了诸如高压需求和生物污染等限制，从而阻碍了许多实际应用。该项目为无电子相关限制的新数字微流体平台提供了直接的途径。所提出的平台利用了一种纯机械手段，以快速，灵活，可编程和可重新配置的方式驱动离散的液滴。该项目还将生成信息和演示材料，这些材料可直接用于促进课堂教学和公众对材料，微流体，界面科学，微/纳米技术的兴趣。该项目旨在使用黑色硅棘轮表面探索动态可调的表面形态和相应的界面润湿性，以寻求一种新的策略来操纵液滴，以提高数字微富集学的发展。提出的棘轮表面涉及弹性体微柱上的超疏水黑色硅尺度，以使单个信号具有实际的单个尺度并改变整个表面形态，形成了驱动液滴的黑色硅棘轮表面。因此，液滴本质上是机械驱动的，而不是电的驱动。此外，预计将集成的黑色硅表面和/或滑入液体注入的多孔表面上的混凝土纳米结构将大大减少生物污染。如果不阐明基本原则并建立必要的技术，就无法实现所提出的方法。将合并两个主要研究人员的专业知识，包括机械师，材料，制造业和微流体，以实现这些理解和知识，并最终在跨智能复合材料和数字微型流体学上开设了一个新的跨学科研究领域。在项目期间，将系统地实现三个目标，以实现项目目标。首先，将研究液滴与超疏水棘轮表面之间的相互作用，并将研究其在其上操纵液滴的相关力。最后，将展示包括液滴运输，合并和分裂以及降低生物污染的液滴操作。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响评估标准来评估，被认为是珍贵的支持。

项目成果

Propulsion reversal in oscillating-bubble powered micro swimmer

振荡气泡动力微型游泳器中的推进反转

• DOI: 10.1088/1361-6439/ac0e7f
• 发表时间: 2021
• 期刊: Journal of Micromechanics and Microengineering
• 影响因子: 2.3
• 作者: Liu, Fang-Wei;Zhan, Ye;Cho, Sung Kwon
• 通讯作者: Cho, Sung Kwon

PDMS-Zwitterionic Hybrid for Facile, Antifouling Microfluidic Device Fabrication

PDMS-两性离子杂化物用于简便、防污微流体装置的制造

• DOI: 10.1021/acs.langmuir.1c03375
• 发表时间: 2022
• 期刊: Langmuir
• 影响因子: 3.9
• 作者: Mercader, Anthony;Ye, Sang-Ho;Kim, Seungil;Orizondo, Ryan A.;Cho, Sung Kwon;Wagner, William R.
• 通讯作者: Wagner, William R.

STRONG MICROSTREAMING FROM A PINNED OSCILLATING MEMBRANE AND APPLICATION TO GAS EXCHANGE

来自固定振荡膜的强微流及其在气体交换中的应用

• 发表时间: 2023
• 期刊: 2023 IEEE Conference on Microelectromechanical systems
• 作者: Anthony L. Mercader;Sung Kwon Cho
• 通讯作者: Sung Kwon Cho