Chemomechanics of Thin Film Detachment in Liquid-Assisted Transfer Printing

转移印刷是一种组装分层结构的技术，在该技术中，在源基板上加工的一层或多层薄膜被拾取并释放到目标基板上。连续地执行该操作，直到形成所需的层状结构。该工艺被广泛应用于微纳薄膜器件的制造，特别是柔性电子产品的生产。在目前的实践中，该技术严重依赖于反复试验，导致产量较低。对于具有多层或离散结构的薄膜的转移尤其如此，在这些薄膜中，损坏和残留污染相当常见。该奖项将重点放在液体环境中薄膜-衬底系统的分离机制的基础研究上。这项研究的结果将通过开发简单的步骤和关系来影响转印工艺的设计和执行，以实现高但高效的生产能力。这项研究是一项涉及化学力学、材料科学和制造业的跨学科研究。研究生和本科生将分别接受广泛的教育和技能培训。来自代表性不足群体的本科生将被积极招募，并将利用一个大学项目来执行K-12外联。转移印刷正在成为一种在制造过程中输送和组装薄膜的有竞争力的技术。它的工作效率本质上是由薄膜从衬底上剥离的机制支撑的。液体辅助转移印花技术可以提高薄膜剥离的产量和质量，并涉及外部机械载荷和固液界面化学反应的协同作用。该项目将对薄膜-衬底系统中的液体辅助界面剥离进行全面的研究，在该系统中，液态水的存在将与界面材料发生反应，导致薄膜层的可控和选择性剥离。这项研究的结果将包括两个方面：1)液体驱动剥离力学的综合化学力学理论；2)一个混合计算模型框架，它将固-液原子相互作用(机理)和薄膜剥离的连续现象(结构功能)与实验测试和理论验证联系起来。这项研究将通过提供科学技术手段来实现高效、定量的生产能力，从而对转移印刷制造技术产生影响。

Transfer printing is a technique of assembling layered structures in which a thin film or layers of thin films processed on a source substrate are picked and released onto a target substrate. This operation is performed successively until the desired layered structure is formed. This process is widely used in the fabrication of micro- to nano-scale thin film based devices, especially in the production of flexible electronics. In current practice, the technique relies heavily on trial and error, which results in low yields. This is particularly true for the transfer of thin films with multiple layers or discrete structures, where damage and residual contamination are quite common. This award will focus on the fundamental study of detachment mechanics of thin film-substrate systems in a liquid environment. The outcome of this research will impact the design and execution of transfer printing process through development of simple steps and relationships for high, yet efficient, throughput. This research is an interdisciplinary study involving chemo-mechanics, materials science and manufacturing. Graduate and undergraduate students will be exposed to and trained on a broad scope of education and skills, respectively. Undergraduate students form underrepresented groups will be actively recruited and a university program will be leveraged to perform K-12 outreach. Transfer printing is emerging as a competitive technique in the delivery and assembly of thin films in manufacturing. Its working efficiency is inherently underpinned by the detachment mechanics of thin films from substrates. The liquid-assisted transfer printing technique could promote both yield and quality of the detachment of thin films and involves a synergistic interplay of external mechanical loading and chemical reactions at the solid-liquid interface. The project will conduct a comprehensive study of liquid-assisted interfacial detachment in film-substrate systems, where the presence of liquid water will react with interfacial materials, leading to a controllable and selective detachment of thin film layers. The outcome of this study will be two-fold: 1) a comprehensive chemomechanics theory of liquid-driven detachment mechanics, and 2) a hybrid computational modeling framework that bridges solid-liquid atomistic interactions (mechanism) and continuum phenomena of film detachment (structural function) with validation from experimental testing and theory. The research will impact the transfer printing fabrication technique by providing scientific and technological means to achieving efficient, quantitative throughput.