Poly(3-hexylthiophene) wrapped carbon nanotube/poly(dimethylsiloxane) composites for use in finger-sensing piezoresistive pressure sensors

• Published in: Carbon (New York) Vol. 49; no. 1; pp. 106 - 110
• Main Authors: Hwang, Jihun, Jang, Jaeyoung, Hong, Kipyo, Kim, Kun Nyun, Han, Jong Hun, Shin, Kwonwoo, Park, Chan Eon
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2011; Elsevier
• Subjects: Carbon; carbon nanotubes; composite polymers; Cross-disciplinary physics: materials science; rheology; Dispersions; electrical conductivity; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Materials science; Multi wall carbon nanotubes; Percolation; Physics; pressure; Pressure sensors; Resistivity; sensors (equipment); Silicone resins; siloxanes; Specific materials; Wrapping; Electrical conductivity; Composite materials; Multiwalled nanotube; Carbon nanotubes; Percolation; Dispersions; Polymers; Carbon
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2010.08.048

[Display omitted] ► MWCNTs/PDMS composite with P3HT shows piezoresistive effect. ► P3HT helps the dispersion of MWCNTs in both solution and composite. ► The concentration of P3HT in the composite affects piezoresistive sensitivity. We fabricated a piezoresistive composite using multi-walled carbon nanotubes (MWCNTs) as a conductive filler and polydimethylsiloxane (PDMS) as a polymer matrix, which operated in the extremely small pressure range required for finger-sensing. To achieve a homogeneous dispersion of MWCNTs in PDMS, the MWCNTs were modified by a polymer wrapping method using poly(3-hexylthiophene) (P3HT). The percolation threshold of the composites was significantly lowered by the presence of P3HT. The electrical conductivity and piezoresistive sensitivity of the composite were found to strongly depend on the P3HT concentration. The well-dispersed P3HT-MWCNT/PDMS composite showed good piezoresistive characteristics in the 0–0.12 MPa pressure range.