title: An electrically and mechanically self-healing composite with pressure- and flexion-sensitive properties for electronic skin applications.
abstract: Pressure sensitivity and mechanical self-healing are two vital functions of the human skin. A flexible and electrically conducting material that can sense mechanical forces and yet be able to self-heal repeatably can be of use in emerging fields such as soft robotics and biomimetic prostheses, but combining all these properties together remains a challenging task. Here, we describe a composite material composed of a supramolecular organic polymer with embedded nickel nanostructured microparticles, which shows mechanical and electrical self-healing properties at ambient conditions. We also show that our material is pressure- and flexion-sensitive, and therefore suitable for electronic skin applications. The electrical conductivity can be tuned by varying the amount of nickel particles and can reach values as high as 40 S cm(-1). On rupture, the initial conductivity is repeatably restored with ∼90% efficiency after 15 s healing time, and the mechanical properties are completely restored after ∼10 min. The composite resistance varies inversely with applied flexion and tactile forces. These results demonstrate that natural skin's repeatable self-healing capability can be mimicked in conductive and piezoresistive materials, thus potentially expanding the scope of applications of current electronic skin systems.
authors.affiliation: Department of Electrical Engineering, Stanford University, David Packard Building, Stanford, CA 94305, USA.
authors.forename: Benjamin C-K
authors.initials: BC
authors.lastname: Tee
authors.forename: Chao
authors.initials: C
authors.lastname: Wang
authors.forename: Ranulfo
authors.initials: R
authors.lastname: Allen
authors.forename: Zhenan
authors.initials: Z
authors.lastname: Bao
mesh_terms: D032701:Biomimetics / Q000379:methods; D004553:Electric Conductivity; D015394:Molecular Structure; D036103:Nanotechnology / Q000379:methods; D011108:Polymers / Q000737:chemistry*; D011312:Pressure; D012867:Skin / Q000737:chemistry*; D013499:Surface Properties; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D011108:Polymers