Highly Exfoliated MWNT-rGO Ink-Wrapped Polyurethane Foam for Piezoresistive Pressure Sensor Applications

Amit Tewari, Srinivas Gandla, Siva Bohm, Christopher R. McNeill, Dipti Gupta

    Research output: Contribution to journalArticleScientificpeer-review

    75 Citations (Scopus)

    Abstract

    The fabrication of pressure sensors based on reduced graphene oxide (rGO) as the sensing material is challenging due to the intrinsic hydrophobic behavior of graphene oxide inks as well as the agglomeration of graphene oxide flakes after reduction. Hydrazine (a reducing agent) and a dual-component additive comprising benzisothiazolinone and methylisothiazolinone in appropriate proportion were used to synthesize a rGO ink with a hydrophilic nature. Utilizing this hydrophilic rGO ink mixed with multiwalled carbon nanotubes (MWNTs), a very simple, low-cost approach is demonstrated for the fabrication of a pressure sensor based on polyurethane (PU) foam coated with the MWNT-rGO ink (MWNT-rGO@PU foam). The MWNT-rGO@PU foam-based devices are shown to be versatile pressure sensors with the potential to detect both small-scale and large-scale movements. At low pressure (below 2.7 kPa, 50% strain), the formation of microcracks that scatter electrical charges results in a detectable increase in resistance suitable for detecting small-scale motion. At a higher pressure, the compressive contact of the coated faces of the PU foam results in a sharp decrease in resistance suitable for monitoring of large-scale motion. Moreover, these sensors exhibit good flexibility and reproducibility over 5000 cycles. The versatility of this sensor has been demonstrated in a wide range of applications, such as speech recognition, health monitoring, and body motion detection. The significant advantages of this sensor are that its cost is low, it is easy to fabricate, and it has a versatility that renders it favorable to health-monitoring applications.
    Original languageEnglish
    Pages (from-to)5185-5195
    Number of pages11
    JournalACS Applied Materials and Interfaces
    Volume10
    Issue number6
    DOIs
    Publication statusPublished - 14 Feb 2018
    MoE publication typeA1 Journal article-refereed

    Keywords

    • microcracks
    • multiwalled carbon nanotubes (MWNTs)
    • piezoresistive pressure sensor
    • polyurethane (PU) foam
    • reduced graphene oxide (rGO)
    • sensitivity

    Fingerprint Dive into the research topics of 'Highly Exfoliated MWNT-rGO Ink-Wrapped Polyurethane Foam for Piezoresistive Pressure Sensor Applications'. Together they form a unique fingerprint.

    Cite this