Three-dimensional Graphene Micro-/Nano-Structures for Advanced Sensor Devices

Superb electromechanical properties of graphene, where large elastic deformation is achievable without significant perturbation of electrical properties, provide a substantial promise for advanced nanoelectromechanical devices, flexible electronics, and wearable bioelectronic devices. In this talk, I describe my group's work on fabrication and processing of three-dimensional graphene micro-/nano-structures for advanced optoelectronic and bioelectronic sensors. First, I will present monolithic synthesis of graphene-graphite for all-carbon transistor arrays. We demonstrate all-carbon device arrays integrated with various soft and flexible surfaces, including wearable contact lens, for potential wearable electronics. Second, I will discuss a rapid and scalable method of creating three-dimensional (3D) micro-/nano-graphene surfaces by soft-matter transformation of shape-memory polymers as well as swelling-induced 3D integration process. Third, we further explore optoelectronic applications of 3D graphene surfaces by developing mechanically reconfigurable optoelectronic sensors with almost 500% improved photo-responsivity compared to conventional graphene optoelectronic sensors. Finally, we explore biosensor device applications by constructing an array of field-effect biosensors and interfacing with muscle and cardiac cells for 3D nano-electrophysiology. I believe our approach to forming three-dimensional graphene micro-/nano-structures offers a unique avenue for creating advanced sensors, and furthermore, these capabilities could be applied to advanced optoelectronics as well as wearable and conformal electronics in the near future.
Dr. SungWoo Nam is an Assistant Professor in the Department of Mechanical Science and Engineering at University of Illinois at Urbana-Champaign (UIUC). He received a B.S. degree in Materials Science and Engineering from Seoul National University, South Korea, where he graduated summa cum laude with the Valedictorian Prize, ranked 1st in the School of Engineering. Following three years of industry experience in carbon nanotube technology (ILJIN Nanotech Co., Ltd.), he obtained his M.A. in Physics (2007) and Ph.D. in Applied Physics (2011) from Harvard University. Following the completion of his Ph.D., he worked as a postdoctoral scholar at the Department of Bioengineering of the University of California, Berkeley. His current research interests at UIUC include (1) investigating new fabrication and processing methods of nano-materials for advanced functions, and (2) exploring engineered nano-materials for multifunctional and flexible electronics.