1. Achieving highly electrical conductivity and piezoresistive sensitivity in polydimethylsiloxane/multi-walled carbon nanotube composites via the incorporation of silicon dioxide micro-particles.
- Author
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Chen, Yi-Fu, Li, Jie, Tan, Yan-Jun, Cai, Jie-Hua, Tang, Xiao-Hong, Liu, Ji-Hong, and Wang, Ming
- Subjects
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ELECTRIC conductivity , *SILICA , *CARBON composites , *STRAIN sensors , *WEARABLE technology , *POLYDIMETHYLSILOXANE - Abstract
Conductive polydimethylsiloxane (PDMS) composites have attracted extensive attention worldwide due to its potential application on wearable electronics and strain sensors. In this work, silicon dioxide micro-particles (μ-SiO 2) were added into the flexible PDMS/multi-walled carbon nanotubes (MWCNT) composites to improve their electrical conductivity and piezoresistive sensitivity. First, the μ-SiO 2 particles can exhibit volume exclusion effect to dense MWCNT fillers in PDMS matrix, which leads to the high electrical conductivity and low percolation threshold. Furthermore, the larger μ-SiO 2 particles could give higher electrical conductivity and lower percolation threshold. For examples, the electrical conductivity and percolation threshold of the PDMS/MWCNT composites with 0.3 vol% MWCNT increased from 3.5 × 10−9 to 2.2 × 10−4 S/m and decreased from 0.44 to 0.08 vol%, respectively, by the incorporation of 30 vol% 85 μm-SiO 2 particles. Second, the piezoresistive sensitivity of PDMS/MWCNT composites was abruptly enhanced by the addition of μ-SiO 2 particles because of the high modulus of μ-SiO 2 particles, which resulted in the asymmetric deformation in the composites. The deformation of PDMS/MWCNT phase was higher in the PDMS/MWCNT/μ-SiO 2 composites than that of the PDMS/MWCNT composites, which leaded to high piezoresistive sensitivity. For example, the gauge factor (GF) of the PDMS/MWCNT composites increased from 1.3 to 62.9 at 30% compression strain by the addition of 30 vol% 1 μm-SiO 2 particles. The highest piezoresistive sensitivity was found in the PDMS/MWCNT/μ-SiO 2 composites with lowest size of μ-SiO 2 particles due to the highest deformation of PDMS/MWCNT phase. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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