Piezoresistive Behavior Study on Finger-Sensing Silicone Rubber/Graphite Nanosheet Nanocomposites

A novel finger‐sensing nanocomposite with remarkable and reversible piezoresistivity is successfully fabricated by dispersing homogeneously conductive graphite nanosheets (GNs) in a silicone rubber (SR) matrix. Because of the high aspect ratio of the graphite nanosheets, the nanocomposite displays a...

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Bibliographic Details
Published in:Advanced functional materials 2007-04, Vol.17 (6), p.898-904
Main Authors: Chen, L., Chen, G. H., Lu, L.
Format: Article
Language:English
Subjects:
Nanocomposites
Piezoelectrics
Sensors
Structure-property relationships
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Summary:A novel finger‐sensing nanocomposite with remarkable and reversible piezoresistivity is successfully fabricated by dispersing homogeneously conductive graphite nanosheets (GNs) in a silicone rubber (SR) matrix. Because of the high aspect ratio of the graphite nanosheets, the nanocomposite displays a very low percolation threshold. The SR/GN nanocomposite with a volume fraction of conductive nanosheets closest to that for the percolation threshold presents a sharp positive‐pressure coefficient effect of the resistivity under very low pressure, namely, in the finger‐pressure range (0.3–0.7 MPa), whereby the abrupt transition could be attributed to compressive‐stress‐induced deformation of the conducting network. The super‐sensitive piezoresistive behavior of the nanocomposite is accounted for by an extension of the tunneling conduction theory which provides a good approximation to the piezoresistive effect. Finger‐pressure sensors may be made from the nanocomposites presented here. The silicone rubber/graphite nanosheet composites with their volume content closest to that of the percolation threshold shows a remarkable positive piezoresistive effect at very low pressures (see figure) that renders them extremely useful as sensors in the finger‐pressure range.
ISSN:1616-301X
1616-3028
DOI:10.1002/adfm.200600519