Controlled Transport of Particles Using Graphene Patterns

We propose the graphene film with trapezoid-shaped nanoparticles (GTNAs) to transport particles. In our design, the conversion of plasmon surface resonances can be realized without changing the excitation light source. By sequentially activating three closely packed potential wells, nanoparticles can be transported between adjacent traps in a creeping manner. Three adjacent potential wells form a linearly repeating array structure, forming a nano-optical conveyor belt. When the resonant wavelength is 5.5 μm, and the power density is 0.4 mW/μm², we verified that the target particle can move along the direction of the hot spots. In addition, the movement of nanoparticles in a liquid environment will be interfered with by viscous resistance and the random Brownian motion process. Since particles produce hysteresis or derailment during transmission, we also analyzed the time interval of switching the Fermi level to manipulate the particle in real-time. The three-dimensional finite-difference time-domain method has been used to verify that the design of this paper provides a conveyor belt in tunable graphene without rotating the polarization angle of the light source and has broad application prospects in biomedical diagnostics.