Flexible and highly pressure-sensitive ternary composites-wrapped polydimethylsiloxane sponge based on synergy of multi-dimensional components

Flexible pressure sensor becomes increasingly important with the development of ultra-sensitive touch technology, electronic skin, and human health monitoring, which requires higher sensitivity. Here, a novel strategy is proposed by designing conductive polymer composites consisting of four components with different dimensions. Through a simple one-step hydrothermal method, the ternary composites of silver-carbon nanotubes-reduced graphene oxide (Ag-CNTs-rGO) were synthesized. The ternary composites-wrapped polydimethylsiloxane (PDMS) sponges, Ag-CNTs-rGO/PDMS, were fabricated by a dip-drying method. The conductive polymer sponges as pressure sensors showed improved sensitivity of 33 kPa(-1) in the range of 0-0.05 kPa, which is twelve times higher than that of the conductive sponge without Ag nanoparticles. The uniform coating of Ag nanoparticles on CNTs and rGO not only enhanced the conductivity of the Ag-CNTs-rGO composites but also reduced the contact resistance between carbon materials. The CNTs-rGO matrix accelerated electron transport throughout the conductive sponge. The good flexible stability of the CNTs-rGO matrix and porous PDMS structures enabled the Ag-CNTs-rGO/PDMS sponge to assemble flexible circuits and act as elastic electric contacts. The combination of zero-dimensional metal nanoparticles, one-dimensional CNTs, and two-dimensional graphene as conductive fillers in three-dimensional porous structures provides new insight into acquiring the ultrahigh-performance flexible pressure sensors.

Automated summary

This study introduces a novel strategy for designing conductive polymer composites, synthesizing ternary composites of silver-carbon nanotubes-reduced graphene oxide, and fabricating pressure sensors with improved sensitivity. The combination of different dimensional components in the composite material provides new insights into achieving ultrahigh-performance flexible pressure sensors.