This grant provides funding to develop roller-based electrostatic printing systems for massively producing pristine, orderly arranged few-layer-graphene structures for scale-up applications in electronics and optoelectronics. The primary research objectives are to (i) experimentally study roll-to-roll and roll-to-plate electrostatic transfer-printing processes, aiming to enable the continuous production of device patterns of few-layer-graphenes on inch-scale wide substrates with a high throughput; (ii) obtain an in-depth understanding of underlying scientific mechanisms associated with the precise exfoliation of atomically layered structures of van der Waals solids through the modeling of roll-to-roll processes using dynamic simulation tools; (iii) quantitatively identify the effects of key processing parameters, such as printing pressure, electric strength, and roller speed on the final printing quality in terms of transfer efficiency, uniformity of graphene thickness over substrates, density of defects, and electrical properties of printed graphenes; and (iv) explore the novel application of electrostatic printing in the fabrication of graphene-based optical devices.
The successful completion of this work will broadly contribute fundamental knowledge in the areas of high-speed manufacturing technologies and significantly expand the capability to process emerging atomically layered materials. It is anticipated that the proposed roll-to-roll electrostatic printing techniques, if successfully realized, will surpass the capability of current technologies for producing few-layer-graphenes in terms of a high degree of material crystallinity comparable to that of the best crystal graphite, a high degree of simplicity for realizing multi-scale patterning, a high roll-to-roll throughput > 50 ft/min, and a low patterning cost less than $2/m2. It also holds the significant potential to be developed into cost-effective, environment-friendly industrial manufacturing processes that can address global needs for addressing future energy needs and US industrial competitiveness. In addition, the program will provide new education and outreach opportunities for involving K-12 students and underrepresented undergraduates into manufacturing-related research activities.
