Optically Modulated Propulsion of Electric-Field-Powered Photoconducting Janus Particles

Herein, we demonstrate the ability to optically tune mobility of electrically powered Janus particles (JPs) that are half-coated with various zinc oxide ($\mathrm{Zn}\mathrm{O}$) semiconducting layers, i.e., polycrystalline, amorphous, and amorphous a ${\mathrm{Si}\mathrm{O}}_{2}$ passivation layer. The $\mathrm{Zn}\mathrm{O}$ semiconductor photoresponse causes an increase in its electrical conductivity light having wavelengths sufficient photon energy respect band gap. This effect, which name modulated electrokinetic propulsion (OMEP), can be harnessed contrast polarizability between dielectric hemispheres, which, turn, results increased mobility. Optical control field enables additional degree JP We also optical modulation collective behavior particle-particle interactions for dense particle populations.