Flexible electronics and wearable electronics are emerging areas, but their widespread adoption is hampered by manufacturing processes that are unreliable, suffer from low-throughput, and are high-cost. Those processes have involved complicated, multi-step microfabrication, material transfer printing, high-vacuum processes, and highly skillful personnel for the integration of multiple components.

That could be coming to an end, thanks to researchers at the Georgia Institute of Technology who have developed a novel nanomanufacturing process to create all-printed, wireless, flexible wearable electronics.

As explained in a recent article published in Nature Communications titled “All-printed nanomembrane wireless bioelectronics using a biocompatible solderable graphene for multimodal human-machine interfaces,” their process involves printing of nanostructured sensors and circuits on a soft elastomeric membrane that can be applied to human skin. Unlike the conventional wearable biosystems, the printed nanomembrane system does not require the use of skin-irritable gels and aggressive tapes, while offering Bluetooth-based wireless data recording and control of external robots.

The research was led by Woon-Hong Yeo, assistant professor in the George W. Woodruff School of Mechanical Engineering, who also has an appointment in the Wallace H. Coulter Department of Biomedical Engineering at Emory University and Georgia Tech. Also contributing were postdoctoral researchers Young-Tae Kwon and Yunsoung Kim.

Yeo and his team demonstrated the performance of the printed electronics by using real-time control of external systems via muscle activities called electromyograms. Placing three wirelessly linked sensors on a forearm, they were able to control the motions of the fingers on a robotic arm with an accuracy rate of about 99% with seven commands. View video

In another demonstration video, the electronics were used to control the movements of a small robotic vehicle.

In the article Yeo and his colleagues highlight the benefits of their method over existing manufacturing processes for printed flexible electronics.

“The ability to manufacture stretchable hybrid electronics entirely based on additive manufacturing methods is particularly attractive due to decreased material consumption, fast turnaround, scalable fabrication based on parallel printing, and, most importantly, the fact that only a single piece of equipment is needed,” says Yeo. “With advances in novel printing methods and soft materials, wearable electronics are transitioning from rigid modalities based on metals and plastics to soft form factors, which offer comfortable, seamless integration with the skin.”

In the future, Yeo sees the research having a range of applications, from healthcare and lifestyle electronics to robotics and prosthetics. The next step in his research is to find clinical applications of wearable bioelectronics for biofeedback-enabled prosthetic development and enhanced rehabilitation training.

Yeo’s research in nanomembrane sensors, stretchable electronics, and human–machine interfaces was recently recognized by Sensors when they awarded him the 2020 Young Investigator Award.

Acknowledgements:

This work was supported by the Georgia Research Alliance based in Atlanta, Georgia. This work was partially supported by the National Institutes of Health under award number (NIH R21AG064309). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. Device preparation was partially supported by the Nano-Material Technology Development Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science, ICT, and Future Planning (2016M3A7B4900044). This work was performed in part at the Georgia Tech Institute for Electronics and Nanotechnology, a member of the National Nanotechnology Coordinated Infrastructure (NNCI), which is supported by the National Science Foundation (ECCS-1542174).