Characterization of MWCNT-PEDOT: PSS Nanocomposite Flexible Thin Film for Piezoresistive Strain Sensing Application

Roopa Hegde,Gurumurthy Hegde,Swapna Peravali,Lavakumar Bathini,Yallappa Shiralgi,Koona Ramji

doi:10.1155/2019/9320976

Abstract

Multiwalled carbon nanotubes (MWCNTs) were synthesized by the reduction of ethyl alcohol with sodium borohydride (NaBH4) under a strong basic solvent with the high concentration of sodium hydroxide (NaOH). Nanocomposites of different concentration of MWCNT dispersed in poly(3,4-ethylene dioxythiophene) polymerized with poly(4-styrene sulfonate) (PEDOT:PSS) were prepared and deposited on a flexible polyethylene terephthalate (PET) polymer substrates by the spin coating method. The thin films were characterized for their nanostructure and subsequently evaluated for their piezoresistive response. The films were subjected to an incremental strain from 0 to 6% at speed of 0.2 mm/min. The nanocomposite thin film with 0.1 wt% of MWCNT exhibits the highest gauge factor of 22.8 at 6% strain as well as the highest conductivity of 13.5 S/m. Hence, the fabricated thin film was found to be suitable for piezoresistive flexible strain sensing applications.

Highlights

Multiwalled carbon nanotubes (MWCNTs) have unique electrical [1] and mechanical properties [2]
We have investigated the effects of using different wt% of synthesized MWCNT in PEDOT: PSS on the conductivity, electrical resistance, and a gauge factor of MWCNT-PEDOT: PSS
Synthesis of MWCNT is performed by the reduction of ethyl alcohol with sodium borohydride (NaBH4) under a strong basic solvent with the high concentration of sodium hydroxide (NaOH)

Summary

Introduction

Multiwalled carbon nanotubes (MWCNTs) have unique electrical [1] and mechanical properties [2]. Polyimide (PI)-MWCNT composites were prepared by in situ polymerization and the nanocomposites showed increasing variation in electrical resistivity with the increasing applied pressure which makes them ideal for fabrication of a polymer pressure sensor [20]. Another piezoresistive response study of MWCNT-PI nanocomposite was demonstrated with different MWCNT concentrations. The electrical properties of MWCNT-PEDOT: PSS thin films under temperature and humidity effects were studied and it was concluded that this nanocomposite is insensitive to humidity and can be used as strain sensors [29]. We have investigated the effects of using different wt% of synthesized MWCNT in PEDOT: PSS on the conductivity, electrical resistance, and a gauge factor of MWCNT-PEDOT: PSS

Experimental Details

Results and Discussion

Conclusion