Abstract: Electroosmosis is an effective way to move fluids in microfluidic devices. The process is driven by the interaction of a double-layer formed at the surface of the fluid in a microspace of the device and the electric field parallel with the surface. Surface conductivity of light sensitive surfaces can be modified by light and thereby the flow pattern of the fluid can be manipulated. The invention relates to a microfluidic device and method to move fluids by electroosmosis and to manipulate flow of the fluid, wherein at least a part the surface adjacent to the fluid driven by electroosmosis is made of a light sensitive material, the surface conductivity of which is modified by changing illumination thereof, thereby flow of the fluid can be influenced. The invention can be used for example in microfluidic channels to manipulate flow velocity, for the preparation of microfluidic switches and mixers or “lab-on-a-chip” devices.

Abstract: A fully light-controllable integrated optical switch applicable in a slab geometry configuration includes a waveguide and an ad-medium in contact with the waveguide. The the ad-medium comprises a photochromic protein as a material of non-linear optical property, wherein switching of a light propagating in the waveguide is effected by a change of an optical property of the ad-medium caused by a light-induced transition of the photochromic protein from one defined molecular state to another.