Divergent effect of electric fields on the mechanical property of water-filled carbon nanotubes with an application as a nanoscale trigger

Abstract

Polar water molecules would exhibit extraordinary phenomena under nanoscale confinement. By means of electric field, the water-filled carbon nanotube (CNT) that has been successfully fabricated in laboratory is expected to make distinct responses to the external electricity. Here, we examine the effect of electric field direction on the mechanical property of water-filled CNTs. It is found that the longitudinal electric field enhances but the transversal electric field reduces the elastic modulus and critical buckling stress of water-filled CNTs. The double-edged effect of electric field is attributed to the competition between the axial and circumferential pressures induced by polar water molecules. Furthermore, it is notable that the transversal electric field could result in an internal pressure with elliptical distribution, which is an effective and convenient approach to apply the nonuniform pressure on nanochannels. Based on a pre-strained water-filled CNTs, we design a nanoscale trigger with the evident and rapid height change started through switching the direction of electric field. The reported finding lays a foundation for the electricity-controlled property of nanochannels filled with polar molecules and provides an insight into the design of nanoscale functional devices.

Bidirectional regulation of configuration of the carbon nanotube containing a water droplet

“…These results demonstrated that the bistability of SWCNTs can be regulated by the electric field combined with the capillary effect. Moreover, compared with previous approaches using either the mechanical [17,18,20,21] or electrical [6,7] methods, the present method is much more convenient and the response of SWCNT is much faster, i.e. in a few picoseconds.…”

“…Interestingly, the collapsed crosssectional configuration causes a continuous reduction of the nanotube's bandgap from 0.92 eV to zero [19], which results in a semiconductor to metal transition, a perfect property for working as potential nanoswitches. The axial loading along the longitudinal direction of the CNTs can also perturb the configuration of the nanotube to change their conductivity [20,21]. However, the application of the mechanical load to the SWCNTs is cumbersome, as the loading direction and amplitude cannot be easily manipulated at the nanoscale.…”

Efficiency of CNT-based rotation transmission nanosystem in water

“…Esmaeilzadeh et al [45] discussed the effect of hydrophobicity on the water flow in a CNT. The interaction between water and CNT has been applied to design different nanodevices [21,[46][47][48][49]. Up to now, to our knowledge, there is no report on the transmission properties of an RTnS in water.…”