Abstract:
In this study, a flexible porous polyvinyl alcohol (PVA)/graphene oxide (GO) composite film
was developed and tested for flexible strain sensing and energy-storage applications.
Morphology and mechanical properties were studied; tensile strength and Young’s modulus
increased by 225% and 86.88%, respectively, at 0.5 wt% GO. The PVA/GO film possesses
exceptional sensing ability to various mechanical strains, such as tension, compression, bending,
and torsion. For example, the gauge factor of the PVA/GO film as a tensile-strain sensor was
measured as 2.46 (246%). Under compression loads, the PVA/GO composite film showed
piezoresistive and capacitive strain-sensing characteristics. Under 5 kPa of compression load, the
relative resistance increased by 81% with a 100 msec response time; the relative capacitance
increased by 160% with a 120 msec response time. The PVA/GO strain sensor exhibited high
durability and reliability over 20 × 103 cycles of tensile strain and bending at 3.33 Hz.
Moreover, the PVA/GO composite film showed good electrochemical properties due to its
porous structure; the maximum capacitance was 124.7 F g−1 at 0.5 wt% GO. After 20 × 103
charging–discharging cycles, the capacitance retention rate was 94.45%, representing high stable
capacitance performance. The results show that electrically conductive porous PVA
nanocomposite films are promising candidates for strain sensing and energy-storage devices