ChEMS Department Seminar

Event Date/Time: 
December 13, 2018 - 9:10am
Event Location: 
3540 EB
Weinan Xu
Bringing the Third Dimension to 2D Materials for 3D Ultrathin Hybrid Bioelectronics


Two-dimensional (2D) layered materials, as a new class of electronic materials, have attracted significant research attention recently, but most of the previous studies utilize the 2D materials in their original planar form and require a rigid and bulky substrate to support the devices, which do not take full advantage of the ultrathin structure and superior flexibility of those 2D materials, they are also limited in generating 3D functional structures and devices. In this talk, I will present a general approach to bring the third dimension to 2D materials, by combining surface chemistry, molecular assembly, microfabrication, and origami folding. The 2D materials are non-covalently surface functionalized with stimuli-responsive polymer brushes, and patterned into uniform predesigned 2D geometries using photolithography. After integrating other functional components such as electrodes and metal nanostructures, the entire ultrathin 2D devices can be transformed into 3D geometry by applying external stimuli, such as temperature, pH, or light, which generates internal strain mismatch in the hybrid layered system. This flexible 3D ultrathin hybrid system provides an ideal platform for biosensing and bioelectronics at the single cell level, as it affords significantly improved contact and communication with soft and irregularly shaped biological samples.


Weinan Xu is currently a postdoctoral fellow in the Department of Chemical and Biomolecular Engineering at Johns Hopkins University, he received his PhD degree in Materials Science and Engineering from Georgia Institute of Technology in 2015, and his B.S. degree in Polymer Science and Engineering from Donghua University, China (2011). His current research is focused on the design, synthesis and assembly of functional polymers and 2D materials, as well as their hybrid structures and devices in 3D geometries for biosensing and bioelectronics. Weinan has published 20 papers in high-impact journals such as Science Advances, Nano Letters, ACS Nano, and Angewandte Chemie. He was recognized with several awards including Excellence in Graduate Polymer Research Award from the American Chemical Society, Best PhD Thesis Award from Sigma Xi and Georgia Tech, and Postdoctoral Fellow Research & Education Award from Johns Hopkins University.