We propose a novel actuation mechanism for colloids, which is based on the Seebeck effect of the electrolyte solution: Laser heating of a nonionic particle accumulates in its vicinity a net charge Q, which is proportional to the excess temperature at the particle surface. The corresponding long-range thermoelectric field provides a tool for controlled interactions with nearby beads or with additional molecular solutes. An external field Eext drags the thermocharged particle at a velocity that depends on its size and absorption properties; the latter point could be particularly relevant for separating carbon nanotubes according to their electronic band structure.
@article{arxiv.1401.7439,
title = {Charging of Heated Colloidal Particles Using the Electrolyte Seebeck Effect},
author = {Arghya Majee and Alois Würger},
journal= {arXiv preprint arXiv:1401.7439},
year = {2014}
}