In order to create nanostructures, polymer foils are irradiated with heavy ions passing completely through the material and modifying it along their trajectories. The number of ions can vary from several billions per square centimetre down to a single ion per sample. Subsequently, the modified material can be dissolved chemically, thus developing nanochannels with geometries (cylindrical, conical, etc.) controllable by the etching process. Ion track-etched membranes are nowadays routinely used for filtration of liquids. Presently, the transport of charged atoms and molecules in particular through single nanopores is studied with respect to the effect of chemical modification and functionalization of the inner pore walls. In future, single-nanopore membranes could be employed as biosensors, taking advantage of their specific transmission properties.

Metals and semimetals are electrochemically deposited in ion track-etched membranes to create nanowires with distinct size and crystalline structure. Since the diameter of the nanowires is comparable to intrinsic length scales (e.g. electron mean free path) it is expected that their physical properties are a function of the wire thickness. Within this context, electrical, optical, and thermal characteristics are investigated including studies of their thermal stability, which is indispensable for future applications. The potential of nanowires for future implementation in commercial devices is enormous. Because of their sharp tips, they are suited as cold field emitters as first tests indicate. In conclusion, nanowires are regarded as promising candidates for components in electronic, optoelectronic, sensoric, and thermoelectric modules.

Besides the basic funding from GSI, these works are currently supported financially by DFG and BMBF projects.