Ultrathin, Crumpled Graphene-Graphite Transistor Arrays for Three-dimensional Bioelectronics

S. Chun, M.C. Wang, R. Han, S. Nam
University of Illinois, Urbana-Champaign, US

Keywords: graphene, bioelectronics

Summary:

Superb electromechanical properties of graphene, where large elastic deformation is achievable without significant perturbation of electrical properties, provide a substantial promise for flexible electronics, advanced nanoelectromechanical and bioelectronic devices. We report three-dimensional (3D) field-effect transistor biosensors built from the monolithic integration of crumpled graphene and graphite. First, we extend from our previous work on monolithic synthesis of graphene-graphite to the synthesis and fabrication of all carbon bioelectronic transistor arrays. Second, we develop a rapid and scalable method of texturing 2-dimensional (2D) graphene by using soft-matter transformation of shape-memory polymers into 3D bioelectronic sensors. We demonstrate that the thermally-induced transformation of graphene on a polymeric substrate creates 3D textured graphene. Quantitative analysis shows that both the wavelength and height of textured graphene are a few micrometers at an applied strain of 300% and that the 3-dimensionality of graphene can be controlled by the processing parameters. We further characterize the electrical and mechanical properties of 3D graphene, and demonstrate the robust electromechanical properties of 3D textured graphene. Finally, we explore biosensor device applications by constructing an array of field-effect biosensors. We believe our unique capabilities could be exploited in chemical and biological detection and conformal interface with biological systems in the future.