Nanoscale continuous cyclic motion driven by a stable thermal field

Abstract

Although considerable efforts have been made to direct nanoscale linear or rotary motion for potential applications in energy conversion and mass transport, generating continuous and cyclic motion in a controlled manner at small scales remains extremely challenging. Based on molecular dynamics simulations, here we propose a nanomotor that can produce continuous cyclic motion. The motor consists of a thick carbon nanotube horizontally clamped between two parallel gold substrates subject to antisymmetric thermal gradients. The speed and motion direction of the motor can be well controlled by the applied thermal field. The driving mechanism is attributed to thermophoresis on solid surfaces, and further confirmed by an analytical model. The present motor design may have general implications not only for developing nanomotors that generate controllable continuous motion but also for developing new techniques of continuously converting other forms of energy into mechanical work.