MWCNT/EPOXY Composite Film as a Structural Strain Sensor for Micro Air Vehicles

Peizo resistive Multiwall Carbon Nano Tubes (MWCNT) /Epoxy based composites film sensors with varying percentage of MWCNTs were developed and the percolation behaviour was studied by electrical conductivity measurements. These films exhibited percolation thresh hold at 2% MWCNT loading. Further, the composite film sensors were characterized in quasi static tensile mode in the range 0-1300 micro strain using a custom designed electrical circuit. The sensitivity of the various composite sensors, estimated in terms of gauge factor was found to be in the range of 40-140 for different percentage loading of MWCNT. To explore the feasibility of these sensors for Micro Air Vehicles (MAVs), static test was carried out by mounting the composite film sensors on MAV wing. The response of the film sensor for bending induced tensile and compressive strains was investigated. Gauge factors of 90 and 80 were realized for tensile and compressive strains respectively. These studies indicated that MWCNT/ Epoxy based composite films are found to be promising candidate for structural strain sensing on MAV.