Carbon nanotube oscillator operated by thermal expansion of encapsulated gases

Abstract

We investigated a carbon nanotube (CNT) oscillator controlled by thermal gas expansionusing classical molecular dynamics simulations. When the temperature rapidly increased,the force on the CNT oscillator induced by the thermal gas expansion rapidly increasedand pushed out the CNT oscillator. As the CNT oscillator extruded from the outernanotube, the suction force on the CNT oscillator increased by the excess van der Waals(vdW) energy. When the CNT oscillator reached the maximum extrusion point, theCNT oscillator was encapsulated into the outer nanotube by the suction force.Therefore, the CNT oscillator could be oscillated by both the gas expansion andthe excess vdW interaction. As the temperature increased, the amplitude of theCNT oscillator increased. At high temperatures, the CNT oscillator escaped fromthe outer nanotube, because the force on the CNT oscillator due to the thermalgas expansion was higher than the suction force due to the excess vdW energy.By the appropriate temperature controls, such as the maximum temperature,the heating rate, and the cooling rate, the CNT oscillator could be operated.