Electro-mechanical transducer based on carbon nanotube network / polystyrene laminate for deformation detection

Abstract

A new type of polystyrene (PS)/carbon nanotube (CNT) network laminate is introduced as an electrically conductive composite material; with favorable properties as electro-mechanical signal transducer capable to detect applied mechanical strain. In course of its fabrication a non-woven polystyrene membrane made by electro spinning was used as filtering mesh for CNT aqueous dispersion. Produced semi-product like filtering membrane with entrapped carbon nanotubes was stuck using solvent of PS on polystyrene test specimen. The electrical resistance of final laminate is sensitive to tensile strain when elongation leads to increase of macroscopic electrical resistance. Test specimens were then tested in the course of monotonic strain growth and also when loading/unloading cycles were imposed. Changes in resistance were found to be reversible, reproducible and deformation can by monitored in real time. Finally, sensitivity to strain can be quantified by means of a gauge factor, GF, which defines sensitivity of strain gauge as a relative resistance change divided by the applied strain. Measured GF for PS/CNT laminates reaches relatively high values, compared with ones of commonly used metallic strain gauges, serving for values of around 13 and applied tensile deformation in range 0.1-0.6 %. These experimental results are really promising serving for real practical application of this principle in course of polymeric based strain gauges or as an integrated PS/CNT units into polystyrene based constructions for their so called "health monitoring".