Techniques, methods, systems, and apparatus are disclosed that are useful for creating addressable three-dimensional elements formed on a flexible substrate using continuous roll-to-roll fabrication methods. An array of conductive elements can be formed on a first flexible substrate layer, over which is disposed a second polymer layer containing a three-dimensional micro-scale relief pattern. The second layer can be formed in registration with the underlying electrode pattern. The lowest areas of the micropattern can be etched away, in order to expose the underlying electrode elements. The 3D micropattern can include a volumetric structure capable of being filled with various materials, where the contents of the 3D structure may be further processed by chemical, electrochemical, or physical treatment. The 3D structure may consist of elements in the general form of microvessels disposed in a periodic or non-periodic array.