The integration of TiOPc-based optoelectronic tweezers and optoelectrowetting with frequency modulation

This paper reports the platform which combines organic photocoductor-based optoelectrowetting (OEW) and optoelectronic tweezers (OET) by spin-coating titanium oxide phthalocyanine (TiOPc) as a photoconductive layer for realizing the manipulation of microparticles and droplets in a single chip. By producing specific image-induced virtual electrodes and modulating the frequency of the electric field on this device, dielectrophoresis (DEP) and electrowetting (EW) can be selected to become dominant force acting on microparticles and droplets. We demonstrate two kinds of operation modes: (1) In OET mode, micropaticles are concentrated by using strip-shaped optical images and the applied voltage in the high frequency range. (2) In OEW mode, droplets are actuated by employing square-shaped optical images and the applied voltage in the low frequency range.