A drug delivery device is provided comprising a housing having an exterior surface, drug ex- pelling means comprising an indicator member arranged to move corresponding to an action performed on or by the drug delivery device, and a carrier foil on which is formed or mounted an energy source, electronically controlled communication means, and a processor adapted to (i) receive input from the drug delivery device indicative of indicator member movement and (ii) control the communication means. The flexible carrier foil is mounted on the exterior of the housing, and the flexible carrier foil is covered at least in part by a sealing foil covering directly or indirectly the thereon formed or mounted components, whereby a sealed interior space for the components formed or mounted on the flexible carrier foil is formed between the housing exterior surface and the sealing foil.
