Flexible and lightweight microcellular RGO@Pebax composites with synergistic 3D conductive channels and microcracks for piezoresistive sensors

• Published in: Composites. Part A, Applied science and manufacturing Applied science and manufacturing, 2019-08, Vol.123, p.222-231
• Main Authors: Dong, Diandian, Ma, Jianzhong, Ma, Zhonglei, Chen, Yongmei, Zhang, Hongming, Shao, Liang, Gao, Jinpeng, Wei, Linfeng, Wei, Ajing, Kang, Songlei
• Format: Article
• Language: English
• Subjects: 3D conductive channels; Microcellular structures; Piezoresistive sensors; Supercritical CO2 foaming
• ISSN: 1359-835X; 1878-5840
• DOI: 10.1016/j.compositesa.2019.05.019

Piezoresistive sensors with high flexibility, lightweight and high sensitivity are crucial in variable conductors and wearable devices. Herein, microcellular poly(ether-block-amide) beads coated with reduced graphene oxide (RGO@Pebax) composites with synergistic 3D conductive channels and microcracks were fabricated via the supercritical CO2 foaming followed by dip-coating hydrogen bond assembly, compression moulding and in-situ reduction. The microcellular RGO@Pebax composites exhibit high flexibility (up to 50% compressibility) and low mass density (down to 0.2 g/cm3) due to the incorporation of microcellular structures and 3D interconnected channels. The resultant microcellular RGO@Pebax composites-based piezoresistive sensors exhibit excellent sensing capacity due to the synergistic effect of double mechanisms: “disconnect-connect” transition of microcracks and increased contact area in the 3D conductive channels. Moreover, the piezoresistive sensors exhibit outstanding reliability and stability during the long-term repeated compression strain. Functional applications of the piezoresistive sensors have been demonstrated, indicating their excellent application potentials in variable conductors and wearable devices.