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

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

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.