Design and analysis of a carbon nanotube-based strain gauge via multiscale modeling
Design and analysis of a carbon nanotube-based strain gauge via multiscale modeling
- Meccanica, 58(8), p.1717-1732, 2023 .
The gauge factor of strain gauges depends on several factors such as the geometry of the gauge and the piezoresistive properties of the materials used. Herein, the piezoresistive response of a strain gauge comprising a network of carbon nanotubes (CNTs)deposited over a polyimide (Kapton)substrate is theoretically and experimentally investigated. Two computational approaches are used, namely, a continuous finite element model and a multiscale model comprising two dimensional scales. The finite element model is a simplified model which simulates the CNT grid as a continuous solid. The multiscale approach utilizes a resistor network model to simulate the change in electrical resistance of the CNT grid with strain and uses such effective electrical resistance as an input of the finite element model. It is found that the gauge factor increases with increased number of end loops, decreasing grid width, and decreasing the end loop height. Both modeling approaches agree with the observed experimental tendencies. The multiscale approach is more realistic and accounts for effects occurring at the micro and nanoscales, such as electron tunneling. The gauge factors predicted by this model were moderately higher than the measured values, given some idealizations of the model.
CARBON NANOTUBE DEPOSIT
STRAIN GAUGE
FINITE ELEMENT
MULTISCALE SIMULATION
PIEZORESISTIVITY
CARBON NANOTUBES
The gauge factor of strain gauges depends on several factors such as the geometry of the gauge and the piezoresistive properties of the materials used. Herein, the piezoresistive response of a strain gauge comprising a network of carbon nanotubes (CNTs)deposited over a polyimide (Kapton)substrate is theoretically and experimentally investigated. Two computational approaches are used, namely, a continuous finite element model and a multiscale model comprising two dimensional scales. The finite element model is a simplified model which simulates the CNT grid as a continuous solid. The multiscale approach utilizes a resistor network model to simulate the change in electrical resistance of the CNT grid with strain and uses such effective electrical resistance as an input of the finite element model. It is found that the gauge factor increases with increased number of end loops, decreasing grid width, and decreasing the end loop height. Both modeling approaches agree with the observed experimental tendencies. The multiscale approach is more realistic and accounts for effects occurring at the micro and nanoscales, such as electron tunneling. The gauge factors predicted by this model were moderately higher than the measured values, given some idealizations of the model.
CARBON NANOTUBE DEPOSIT
STRAIN GAUGE
FINITE ELEMENT
MULTISCALE SIMULATION
PIEZORESISTIVITY
CARBON NANOTUBES