Graphene woven fabric/polydimethylsiloxane composites as flexible strain and temperature sensors for wearable applications

Graphene woven fabrics (GWFs) are fabricated by template-directed chemical vapor deposition on Ni templates. Freestanding GWFs with orthogonally interconnected graphene tubes are obtained after etching Ni frameworks. One layer of freestanding GWF is deposited onto a flexible and stretchable polydimethylsiloxane (PDMS) substrate. The change in electrical resistance (ΔR) relative to the original resistance (R₀) is continuously monitored as a function of applied strain while the GWF/PDMS composite is subjected to cyclic uniaxial tension. The normalized resistance of the composite shows a ∼ 670% increase at a tensile strain of 3% and is recovered to zero upon unloading during the loading/unloading cycles, indicating that the composite can be used as flexible strain sensors within the reversible strain range. Besides strain, the composite also shows a normalized resistance change of ∼ 400% with a temperature increase from ambient to 100°C, confirming a sufficient sensitivity for use as temperature sensors. Such lightweight and highly sensitive, conductive GWF/PDMS composites are excellent candidates as flexible sensors for emerging wearable applications. A wearable musical instrument is demonstrated with integrated GWF/PDMS composites as flexible motion sensor so that one can easily produce music by hand gestures through cellphones.