title: Sensitive, high-strain, high-rate bodily motion sensors based on graphene-rubber composites.
abstract: Monitoring of human bodily motion requires wearable sensors that can detect position, velocity and acceleration. They should be cheap, lightweight, mechanically compliant and display reasonable sensitivity at high strains and strain rates. No reported material has simultaneously demonstrated all the above requirements. Here we describe a simple method to infuse liquid-exfoliated graphene into natural rubber to create conducting composites. These materials are excellent strain sensors displaying 10(4)-fold increases in resistance and working at strains exceeding 800%. The sensitivity is reasonably high, with gauge factors of up to 35 observed. More importantly, these sensors can effectively track dynamic strain, working well at vibration frequencies of at least 160 Hz. At 60 Hz, we could monitor strains of at least 6% at strain rates exceeding 6000%/s. We have used these composites as bodily motion sensors, effectively monitoring joint and muscle motion as well and breathing and pulse.
authors.affiliation: School of Physics, CRANN and AMBER, Trinity College Dublin , Dublin 2, Ireland.
authors.forename: Conor S
authors.initials: CS
authors.lastname: Boland
authors.forename: Umar
authors.initials: U
authors.lastname: Khan
authors.forename: Claudia
authors.initials: C
authors.lastname: Backes
authors.forename: Arlene
authors.initials: A
authors.lastname: O'Neill
authors.forename: Joe
authors.initials: J
authors.lastname: McCauley
authors.forename: Shane
authors.initials: S
authors.lastname: Duane
authors.forename: Ravi
authors.initials: R
authors.lastname: Shanker
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Izabela
authors.initials: I
authors.lastname: Jurewicz
authors.forename: Alan B
authors.initials: AB
authors.lastname: Dalton
authors.forename: Jonathan N
authors.initials: JN
authors.lastname: Coleman
mesh_terms: D004548:Elasticity; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D008991:Monitoring, Physiologic / Q000295:instrumentation*; D009068:Movement; D012408:Rubber / Q000737:chemistry*; D013314:Stress, Mechanical
chemical_list: D006108:Graphite; D012408:Rubber
keywords: bodily motion sensors; dynamic strain; graphene−rubber composites; strain sensors