Fabrication and Characterisation of carbon nanotube composites for strain sensor applications

Abstract

This paper reports on the fabrication of carbon nanotube (CNT) composites based on poly-dimethylsiloxane (PDMS). Both composites using multiwalled carbon nanotubes (MWCNTs) as well as composites using vertically aligned carbon nano-tubes (VACNTs) as conductive filler elements have been investigated. The MWCNT/PDMS composites show a quasi-linear piezoresistance response with gauge factors between 0.8 and 2.3. The VACNT/PDMS composites behave in a similar way realizing a gauge factor of 1.4. This gauge factor can be explained by only considering the geometrical change of the VACNT/PDMS composites during strain. The dense network of vertically aligned carbon nanotubes limits the contraction or tranver-sal strain during axial strain of the VACNT/PDMS composites. Poisson's ratio drops from 0.45 for pure PDMS to 0.2 for VACNT/PDMS composites. Conclusions about the suitability of these materials for use in MEMS are presentedstatus: publishe