Rotational Dynamics and Heating of Trapped Nanovaterite Particles

arita2016acsnanoYoshihiko Arita, Joseph Richards, Michael Mazilu, Gabriel Spalding, Susan E. Skelton Spesyvtseva, Derek Craig, and Kishan Dholaia

ACS Nano 10(12), 11505-11510  (2016)

doi: 10.1021/acsnano.6b07290

We synthesise, optically trap and rotate individual nanovaterite crystals with a mean particle radius of 423nm. Rotation rates of up to 4.9kHz in heavy water are recorded. Laser-induced heating due to residual absorption of the nanovaterite particle results in the superlinear behaviour of the rotation rate as a function of trap power. A finite element method based on the Navier-Stokes model for the system allows us to determine the residual optical absorption coefficient for a trapped nanovaterite particle. This is further confirmed by the theoretical model. Our data show that the translational Stokes drag force and rotational Stokes drag torque needs to be modified with appropriate correction factors to account for the power dissipated by the nanoparticle.