title: Ultrafast Self-Healing Nanocomposites via Infrared Laser and Their Application in Flexible Electronics.
abstract: The continuous evolution toward flexible electronics with mechanical robust property and restoring structure simultaneously places high demand on a set of polymeric material substrate. Herein, we describe a composite material composed of a polyurethane based on Diels-Alder chemistry (PU-DA) covalently linked with functionalized graphene nanosheets (FGNS), which shows mechanical robust and infrared (IR) laser self-healing properties at ambient conditions and is therefore suitable for flexible substrate applications. The mechanical strength can be tuned by varying the amount of FGNS and breaking strength can reach as high as 36 MPa with only 0.5 wt % FGNS loading. On rupture, the initial mechanical properties are restored with more than 96% healing efficiency after 1 min irradiation time by 980 nm IR laser. Especially, this is the highest value of healing efficiency reported in the self-healable materials based on DA chemistry systems until now, and the composite exhibits a high volume resistivity up to 5.6 × 1011Ω·cm even the loading of FGNS increased to 1.0 wt %. Moreover, the conductivity of the broken electric circuit which was fabricated by silver paste drop-cast on the healable composite substrate was completely recovered via IR laser irradiating bottom substrate mimicking human skin. These results demonstrate that the FGNS-PU-DA nanocomposite can be used as self-healing flexible substrate for the next generation of intelligent flexible electronics.
authors.affiliation: Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.|Nano Science and Technology Institute, University of Science and Technology of China (USTC) , Suzhou 215123, China.
authors.forename: Shuwen
authors.initials: S
authors.lastname: Wu
authors.affiliation: Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.
authors.forename: Jinhui
authors.initials: J
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.|School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.
authors.forename: Guoping
authors.identifier: http://orcid.org/0000-0002-0683-495X
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.affiliation: Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences , Shenzhen 518055, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Sun
authors.affiliation: School of Materials Science and Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States.|Faculty of Engineering, the Chinese University of Hong Kong 999077, Hong Kong, China.
authors.forename: Chingping
authors.initials: C
authors.lastname: Wong
keywords: Diels−Alder chemistry; flexible electronics; graphene; self-healing; substrate