CNT-based gauge

The relative incremental cost (AC), representing the increased cost due to the more expensive CNT-based gauge, is taken as ... 

Figure 15.3. Effect of relative importance of performance to cost on the competitive cost of the CNT gauge for gauges with GCNT = 5 and 15. The solid lines represent limits on the cost of the CNT-based gauge.

Cost-Benefit Analysis of Conventional Foil Gauges vs. CNT-Based Composite Gauges... 

When seeking a polymer material for a CNT-based strain gauge, ductility and ease of processing are the key requirements. For that reason, polymethyl methacrylate (PMMA) and polyethylene (PE) are two candidate materials. Studies on the electrical conductivities of CNT-PMMA composites reported minimum percolation thresholds ranging from 0.084 to 1.3 wt% which depend on the type of CNT (SWNT or MWNT) and the dispersion technique. Such values are much lower than percolation thresholds reported for CNT-PE which rise up to 15 wt% (38). As a consequence, much higher conductivity values were reported for CNT-PMMA composites. For this reason, a PMMA matrix will be considered for the current... 

The proposed CNT-based composite gauge in this case study is assumed to be a thin film of a flexible thermoplastic polymer to which the CNTs are added and dispersed using the techniques described in (37,48). The produced thin film is then cut into small dimensions equivalent to those of conventional foil gauges. The cost of CNT-based film strain gauge is based on the material cost of a film of 15 mm x 50 mm x approximately 0.15 mm thickness using a density of PMMA = 1.2 g/cc, density of SWNT = 1.4 g/cc and density of MWNT = 1.9 g/cc. Table 15.4 summarizes the properties of the materials used. 

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