Effect of electric field on mechanical behavior of vertically-aligned carbon nanotube structures

Here, we summarize various reports on the mechanical response of vertically aligned carbon nanotubes forest (CNTF) structures under an applied electric field. Quasi-static compression tests on CNTF structures show a dramatic strengthening by application of the electric field both in low-strain (linear) and high strain (nonlinear) regimes. The CNTF structures also show a finite hysteresis, i.e., energy dissipation, in stress-strain behavior during a loading-unloading cycle. Tests demonstrate that the application of an electric field can tailor the energy absorption capacity of CNTF structures. In practice, the energy absorption capacity of CNTF structures increases by several folds when the loading and unloading (under quasi-static strain rates) are performed in the presence and the absence of the electric field, respectively. However, the improvement in the energy absorption capacity decreases drastically at higher strain rates. Additionally, applying an electric field improves the creep resistance of the CNTF structures. Overall, the summarized studies show promising electro-mechanical properties of CNTF structures which are helpful in developing the next generation of nano-and micro-electro-mechanical devices and sensors.