NSF Award for Roll-to-Roll Printing of Multi-layer Flexible Substrate Electronics
When you think about electronics, such as solar panels and transistors, the first that comes to mind is probably not printing. But a promising advanced manufacturing technology for high-volume production of electronic devices is roll-to-roll printing—a technique that can continuously transfer a printed electronic pattern onto multi-layer flexible substrates.
“Compared to traditional manufacturing, roll-to-roll printing is much more efficient and even has a hand in nanoscale products,” said Mechanical and Industrial Engineering Assistant Professor Xiaoning Jin. “It’s a huge input, high-yield manufacturing process which is different from traditional sheet-by-sheet and the batch-based manufacturing process. It’s also particularly efficient for large-scale manufacturing of electronic devices.”
But the process to refine roll-to-roll printing continues and it is a complicated one. Multilayer electronics need tight alignment and one of the problems is in how to make it stay within specifications.
Jin is principal investigator of a $544K National Science Foundation grant, working with Hongli Zhu, an assistant professor in the same department, to improve this very issue through modeling and virtual sensor-based control.
Jin brings her focus on industrial artificial intelligence technology for smart manufacturing to the project while Zhu offers a specialty in material sciences for paper electronics and printing materials for advanced and electronic devices. They are in collaboration with the University of Massachusetts-Amherst, which Zhu believes might have the largest roll-to-roll manufacturing facility nationwide.
“Due to limitation of current technology for real-time monitoring, we don’t have visibility into what’s going on in this printing process,” Jin explained. “We want to collect from the controllers, optical sensors, and multiple sources of data to estimate and review the actual state of the process in what we call virtual sensing. That will help us resolve the problem of misalignment because the whole process is in multiple stages of one roller to another. We want to attack the real-time errors in terms of position of geometry errors in the printing process.” This, she said, will provide adaptive control to avoid error from propagation of accumulation and the hope is the end-of-line printed products will get a lower defect rate and achieve a higher through-put and yield alignment.
For a proposed multilayer transistor, the goal is to have the resolution of a function device within 20 micro. “If we can control the deviation within that limit then we can guarantee the normal functionality or performance of the printed device,” Jin said.
“Paper is a historic substrate used for R2R printing,” Zhu mentioned. She also points out that there is a possible crucial ecological effect if the study is successful. “If we can improve paper electronic for manufacturing, then it improves the usage of sustainable materials, which is biodegradable in the environment,” she says. “The issue of plastic pollution can’t be ignored.”
Jin reminds that this is a high-yield manufacturing process which can even stretch to the biomedical world through devices. “The process of how electronics are being created is fascinating and often overlooked,” Jin said. “Many people are hoping for a better way.”