S Figure four. (a) The experimental The experimental set-up of the piezoresistive sensing test and (b) the CNM-incorporated Figure four. (a) set-up in the piezoresistive sensing test and (b) the CNM-incorporated FRP composites mounted within the UTM. mounted within the UTM. composites mounted within the UTM. FRP(a)4. Results 4.1. Electrical Properties Figure 5a shows the relationship amongst the electrical resistance of CNM-incorporated GFRP AAPK-25 custom synthesis samples and also the quantity of incorporated CNMs. The pure GFRP sample, without incorporated CNMs, exhibited an electrical resistivity greater than 100 G , because it was composed of insulating materials, namely epoxy resin and glass fiber [42]. Electrical conductivity networks GNE-371 supplier formed inside the GFRP, as the CNMs have been incorporated within the GFRP,four.1. Electrical PropertiesSensors 2021, 21,Figure 5a shows the relationship amongst the electrical resistance of CNMrated GFRP samples as well as the quantity of incorporated CNMs. The pure GFRP without having incorporated CNMs, exhibited an electrical resistivity higher than one hundred G 7 of 19 it was composed of insulating supplies, namely epoxy resin and glass fiber [42]. E conductivity networks formed within the GFRP, as the CNMs have been incorporated in th which decreased the electrical resistance of your GFRP samples. As shown in Figur electrical resistance decreased dramatically when the in Figure 5a, CNM quan which decreased the electrical resistance of the GFRP samples. As shown incorporated the equal to or greater than 1.5 wt. , regardless of CNM variety. This result indicated electrical resistance decreased drastically when the incorporated CNM quantity was incorporated CNMs in the of CNM components outcome indicated that the equal to or greater than 1.5 wt. , regardlessinsulatingtype. This lowered their electrical resistanc incorporated CNMs in the intrinsic properties from these of electrical resistance,of conductors. In a ing their insulating materials decreased their insulators to these altering their intrinsic properties found that of insulators to those of conductors. Additionally, it was it was from these GFRP samples with just CNTs or both CNTs and graphene discovered that GFRP samples with just CNTs or each CNTs the other samples that included GNPs much larger electrical conductivity than and graphene showed considerably larger electrical(Figure 5b). This wasthe other samples that incorporated GNPs or CNFs indica conductivity than attributed for the electrical conductivity with the CNMs, (Figure 5b). This the conductivity of CNT and graphene was higherCNMs, indicating thatThis resu was attributed towards the electrical conductivity in the than GNPs or CNFs. the conductivity of CNT and graphene was greater than GNPs studies [22]. Wang et al. in close agreement with outcomes from prior or CNFs. This outcome was (2020) inv close agreement with final results from preceding research [22]. Wang et al. (2020) epoxy-based compos the effects of CNM type on the electrical conductivity of investigated the effects of CNM kind on thethat composites with CNT epoxy-based showed higher electrical demonstrated electrical conductivity of or graphene composites, and demonstrated that composites with CNT or graphene showed greateraddition, the percolation t tivity than composites with CNFs or GNPs [22]. In electrical conductivity than composites with CNFs or GNPs [22]. Furthermore, the percolation threshold in elec phenomenon was observed in Figure 5a, indicating a dramatic reduction phenomenon was observed in Figure 5a, indicating a dramatic reduction in ele.