A very interesting behavior is observed upon irradiation of 9 using a photomask of very narrow inscription lines in PS, which leads to a persistent 3D-relief formation in the irradiated areas (Figure and). The specific molecular cause for this behavior is currently under investigation in our laboratory, but a strong local accumulation of charged ring closed 9 species and concomitant localized polymer adjustments and packing changes seem likely to be important. Evidence for the presence of charged 9 isomers is directly obtained from the localized color changes, which coincide with the 3D structured polymer areas. Such behavior can be used to inscribe information in a haptic way instead of relying on optical changes, which is of potential interest for applications in braille displays, or reprogrammable stamps, for example. After diluting the material with benzene and allowing the chromophore to thermally isomerize to the open 9 form at ambient temperature, the imprint is erased and a smooth surface is obtained into which a different 3D-relief can be inscribed again (Figure ). With this series of experiments reversibility of the 3D inscription process is demonstrated a unique application area for aza-diarylethene photoswitches.