High-aspect-ratio polymeric structures have been fabricated using a process that combines reactive ion etching (RIE) and stress-oriented, shrinkable polystyrene films. It is reported how after pat patterning of the surface of the polystyrene film by RIE, heating of the film caused it to shrink by a factor of 4-5 in the lateral dimensions while the thickness of the film and the features on it increased by a factor of similar to 20 (see Figure).