A Scalable Roll-to-Roll Printing Approach to Integrating Nanomaterials into High-Performance Devices

在过去的几十年里，各种高质量的纳米材料的出现带来了新的可调性能，可以设想新的和改进的技术。前景包括具有前所未有的功率转换效率的低成本太阳能电池到高对比度生物医学成像剂。虽然已经证明了结合纳米级材料的实验室规模器件的高性能，但对于许多应用，如光电子器件和显示器，高效率器件和器件阵列的可扩展制造是绝对必要的。目前，还没有明确的途径来实现这种实际的大面积、大阵列的复杂、高性能结构。该奖项支持基础研究，为开发可扩展的卷对卷打印方法建立必要的基础，以在功能器件架构内组装大型纳米级材料阵列。这种集成大型纳米级材料阵列的能力应该能够制造从高性能太阳能电池到节能显示器和照明技术的各种各样的电子和光电器件。这种涉及材料，机械和制造科学以及光电子学的多学科研究将为来自代表性不足的群体的学生提供研究机会，并促进/加强工程教育。各种0 D，1D和2D纳米材料的异质集成，如量子点，碳纳米管，和石墨烯形成垂直堆叠的多层结构，允许有效的方法利用这些纳米材料在整体结构然而，成熟的制造工艺，如光刻法，往往与纳米材料不兼容。使用弹性体印模的干式转印是这种不相容性问题的潜在解决方案，但是弹性体的动力学可切换粘附的性质需要在取回和印刷步骤之间的不同剥离速度。这种要求又在将弹性体印模用于可缩放的卷对卷印刷中引入了巨大的挑战，因为检索和印刷需要用相同的辊来执行，因此需要相同的剥离速度。本研究旨在探讨形状记忆聚合物作为印模材料，以取代干粘合的刚度控制的动力学控制，并进一步提高粘合力和可切换性。研究小组将研究用于转移印刷的形状记忆聚合物的力学，研究纳米材料的基本特性和使用形状记忆聚合物组装的界面，并将获得的知识应用于组装由纳米材料和其他相关设备组件组成的多层堆叠。

The emergence of a variety of high quality nanoscale materials in the last few decades have brought forth novel tunable properties with which new and improved technologies can be envisioned. Prospects include low-cost solar cells with unprecedented power conversion efficiencies to high-contrast biomedical imaging agents. While high-performance in laboratory scale devices incorporating nanoscale materials have been demonstrated, for many applications such as photovoltaics and displays, scalable manufacturing of high efficiency devices and device arrays is an absolute necessity. Currently, there are no clear pathways to achieving such practical large area, large arrays of complex, high performing structures. This award supports fundamental research to build the necessary foundation for developing a scalable roll-to-roll printing approach to assembling large arrays of nanoscale materials within functioning device architectures. Such an ability to integrate large arrays of nanoscale materials should enable manufacturing of a wide variety of electronic and optoelectronic devices from high-performance solar cells to energy efficient displays and lighting technologies. This multidisciplinary research involving materials, mechanical and manufacturing sciences as well as optoelectronics will provide research opportunities for students from underrepresented groups and promote/enhance engineering education.Heterogeneous integration of various 0D, 1D, and 2D nanomaterials such as quantum dots, carbon nanotubes, and graphene into vertically stacked multilayer structures allows for effective methods of utilizing the unique electrical and optical properties of these nanomaterials in a monolithic architecture. However, well-established fabrication processes such as photolithography are often incompatible with nanomaterials. Dry transfer printing using elastomeric stamps is a potential solution to this incompatibility problem but the nature of kinetically switchable adhesion of elastomers requires different peeling speeds between retrieval and printing steps. This requirement in turn introduces a grand challenge in employing elastomeric stamps to scalable roll-to-roll printing since retrieval and printing need to be carried out with the same roller, thus the same peeling speed. This research aims to explore shape memory polymers as stamp materials to replace kinetic control by stiffness control of dry adhesion and, furthermore, to enhance the adhesion force and switchability. The research team will examine the mechanics of shape memory polymers for transfer printing, investigate the fundamental properties of nanomaterials and interfaces assembled using shape memory polymer and apply the knowledge gained to assemble multilayer stacks consisting of nanomaterials and other relevant device components in a continuous roll-to-roll fashion.