A device and method of its production for a micro-channel thermal absorber to be used as a solar thermal collector, heat collector, or heat dissipater, extruded or continuously cast in one piece or in modular segments from a metal, plastic, or glass and assembled into panels of different structures seamlessly integrated into the envelope of a building as covering layers or structural elements. The micro-channel thermal absorber comprises an active plate, a back plate adjacent to the active plate, and a plurality of micro-channel walls arranged substantially perpendicular to the active plate and the back plate to define a plurality of fluid transport micro-channels configured to allow fluid flow there-along, wherein the micro-channel walls constitute supporting elements between the active plate and the back plate to provide structure.