Fabrication and characterization of hybrid carbon nanotube for skins sensing application

An emerging technology of advance flexible sensor based on carbon nanotube (CNT) has gained attention for various applications in health monitoring, human motion monitoring and artificial intelligence (AI). Flexible sensing skin-type sensor like strain sensor acts as a transducer that provides signal under various spatial and impact condition. In this work, CNT-based flexible strain sensors were fabricated using polydimethylsiloxane (PDMS), polytetrafluoroethylene (PTFE) and Ecoflex with different CNT concentration to produce a high sensitivity with low surface wettability hybrid nanocomposite sensor. The hybrid CNT nanocomposites were fabricated via drop casting method. This work was carried out to investigate the effect of different CNT concentration on the CNT dispersion in the hybrid nanocomposite. Electrical properties which are conductivity and sensitivity were measured and analyzed under different static strain cycle up to 60%. The results show that as strain increases the capacitive response becomes predominant rather than the resistive response which indicates that the piezo capacitive is the ideal response in achieving high sensitivity at higher strain. Surface wettability characterization was done to examine the water- repellency effect for different types of nanocomposites. Surfacewettabilityexhibitsan increase of water contact angle in each composite after the incorporation of polytetrafluoroethylene (PTFE) which reduce the surface wettability to become more hydrophobic. It was found that 2 wt% CNT/PDMS/PTFE hybrid nanocomposite presented a satisfactory response with a relatively high conductivity of 0.05023 S/m, high sensitivity at 44.246 and high water contact angle of 151.24° that classified as hydrophobic. This work would provide important characterization to better understand CNT-based hybrid nanocomposites and their sensing performance.