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Ultrasensitive Strain Gauges Enabled by Graphene‐Stabilized Silicone Emulsions
Author(s) -
O’Mara Marcus A.,
Ogilvie Sean P.,
Large Matthew J.,
Amorim Graf Aline,
Sehnal Anne C.,
Lynch Peter J.,
Salvage Jonathan P.,
Jurewicz Izabela,
King Alice A. K.,
Dalton Alan B.
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202002433
Subject(s) - materials science , gauge factor , graphene , silicone rubber , composite material , silicone , elastomer , microstructure , emulsion , silicone oil , strain gauge , nanocomposite , nanotechnology , chemical engineering , medicine , alternative medicine , pathology , fabrication , engineering
Abstract Here, an approach is presented to incorporate graphene nanosheets into a silicone rubber matrix via solid stabilization of oil‐in‐water emulsions. These emulsions can be cured into discrete, graphene‐coated silicone balls or continuous, elastomeric films by controlling the degree of coalescence. The electromechanical properties of the resulting composites as a function of interdiffusion time and graphene loading level are characterized. With conductivities approaching 1 S m −1 , elongation to break up to 160%, and a gauge factor of ≈20 in the low‐strain linear regime, small strains such as pulse can be accurately measured. At higher strains, the electromechanical response exhibits a robust exponential dependence, allowing accurate readout for higher strain movements such as chest motion and joint bending. The exponential gauge factor is found to be ≈20, independent of loading level and valid up to 80% strain; this consistent performance is due to the emulsion‐templated microstructure of the composites. The robust behavior may facilitate high‐strain sensing in the nonlinear regime using nanocomposites, where relative resistance change values in excess of 10 7 enable highly accurate bodily motion monitoring.