Fundamentals of Self-Aligned Capillary-Assisted Processes for Flexible Electronics

柔性电子产品的目标是将联合收割机的电子功能与机械灵活性结合起来，以实现柔性显示器、可穿戴电子产品和柔性照明产品等应用。高性能电子器件需要精细的尺寸和精确对齐的多种电子材料层;因此，该领域的关键挑战是开发能够在柔性基板上经济地生产这些架构的制造平台。该奖项支持一种新的基于液体墨水的制造工艺的基础研究，称为电子自对准毛细管辅助光刻（或SCALE）。SCALE有可能成为印刷柔性电子领域的颠覆性技术，因为它消除了一个重要的技术障碍，即需要精确对齐功能油墨的印刷层，降低了成本，并使基于柔性电子的新产品成为可能，这将改善我们的生活质量。 基础研究将影响许多科学和工程领域，包括印刷电子，电子墨水开发，流体力学和界面现象。 这些努力还包括旨在留住工程学新生的研究经验，制造教育材料的开发以及与工业界的联系。SCALE涉及在柔性基底上压印多层，凹陷的开放式储液器网络，毛细管和设备结构，通过喷墨打印将电子功能墨水输送到储液器中，并使用毛细管作用选择性地和顺序地填充特征以创建电子元件，器件和电路。SCALE有很多优点：它是附加的、自对准的、高度平行的、服从卷对卷（R2 R）处理，并且在可制造性和衬底面积方面是可缩放的。基于SCALE的导电网络、电容器、电阻器和薄膜晶体管的特征尺寸在~5 μm及以下的范围内，但另一方面，用于油墨输送的目标容器大一个数量级，这使得R2 R方法成为可能。 这项研究使用了流体力学建模，基本处理实验（包括高速可视化）和电子墨水开发的综合方法，以揭示R2 R SCALE的科学和工程。该团队将在涂层工艺和可视化实验室中使用独特的多功能R2 R涂层和印刷设备，以及R2 R纳米压印设备来演示全R2 R方法。

The goal of flexible electronics is to combine electronic functionality with mechanical flexibility to enable applications such as flexible displays, wearable electronics and flexible lighting products. High performance electronic devices require fine dimensions and precisely aligned layers of multiple electronic materials; hence, a key challenge in the field is developing a manufacturing platform capable of economically producing these architectures on flexible substrates. This award supports fundamental research on a new, liquid ink-based manufacturing process known as Self-Aligned Capillarity-Assisted Lithography for Electronics (or SCALE). SCALE has the potential to be a disruptive technology in the field of printed flexible electronics, because it removes a significant technological barrier, the need to precisely align printed layers of functional ink, reduces cost, and makes possible flexible electronics-based new products that will improve our quality of life. The fundamental studies will impact many scientific and engineering fields, including printed electronics, electronic ink development, fluid mechanics and interfacial phenomena. The efforts also include research experiences designed to retain freshmen in engineering, development of manufacturing educational materials and outreach to industry.SCALE involves imprinting a multilevel, recessed open network of reservoirs, capillaries and device structures on a flexible substrate, delivering electronically functional inks into the reservoirs by inkjet printing and using capillarity to selectively and sequentially fill features to create electronic components, devices and circuits. SCALE has many advantages: it is additive, self-aligned, highly parallel, amenable to roll-to-roll (R2R) processing, and scalable in terms of manufacturability and substrate area. SCALE-based conductive networks, capacitors, resistors and thin film transistors have features sizes in range of ~5 µm and below, but the target reservoirs for ink delivery, on the other hand, are an order of magnitude larger, which enables the R2R approach. This research uses a combined approach of fluid mechanics modeling, fundamental processing experiments, including high speed visualization, and electronic ink development to uncover the science and engineering of R2R SCALE. The team will use a unique Multifunctional R2R Coating and Printing Apparatus in the Coating Process and Visualization Lab, as well as a R2R nanoimprinting apparatus to demonstrate an all R2R approach.