title: Sensitive electromechanical sensors using viscoelastic graphene-polymer nanocomposites.
abstract: Despite its widespread use in nanocomposites, the effect of embedding graphene in highly viscoelastic polymer matrices is not well understood. We added graphene to a lightly cross-linked polysilicone, often encountered as Silly Putty, changing its electromechanical properties substantially. The resulting nanocomposites display unusual electromechanical behavior, such as postdeformation temporal relaxation of electrical resistance and nonmonotonic changes in resistivity with strain. These phenomena are associated with the mobility of the nanosheets in the low-viscosity polymer matrix. By considering both the connectivity and mobility of the nanosheets, we developed a quantitative model that completely describes the electromechanical properties. These nanocomposites are sensitive electromechanical sensors with gauge factors >500 that can measure pulse, blood pressure, and even the impact associated with the footsteps of a small spider.
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Conor S
authors.initials: CS
authors.lastname: Boland
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Umar
authors.initials: U
authors.lastname: Khan
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Gavin
authors.initials: G
authors.lastname: Ryan
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Barwich
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Romina
authors.initials: R
authors.lastname: Charifou
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Andrew
authors.initials: A
authors.lastname: Harvey
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Claudia
authors.initials: C
authors.lastname: Backes
authors.affiliation: National Graphene Institute and School of Materials, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Zheling
authors.initials: Z
authors.lastname: Li
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Mauro S
authors.initials: MS
authors.lastname: Ferreira
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland.
authors.forename: Matthias E
authors.initials: ME
authors.lastname: Möbius
authors.affiliation: National Graphene Institute and School of Materials, University of Manchester, Manchester M13 9PL, UK.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Young
authors.affiliation: School of Physics, Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN) and Advanced Materials and Bioengineering Research (AMBER) Research Centers, Trinity College Dublin, Dublin 2, Ireland. colemaj@tcd.ie.
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Coleman
mesh_terms: D000818:Animals; D001795:Blood Pressure Determination / Q000295:instrumentation*; D004548:Elasticity; D017097:Electric Impedance; D006108:Graphite; D000070276:Heart Rate Determination / Q000295:instrumentation*; D006801:Humans; D055595:Mechanical Phenomena; D053761:Nanocomposites; D011108:Polymers; D012828:Silicones; D013112:Spiders; D014783:Viscosity; D016138:Walking
chemical_list: D011108:Polymers; D012828:Silicones; D006108:Graphite