For the separation of low molecular weight gases like Helium (He) or Hydrogen (H2), very often membrane processes are used. The Quartz and Palladium thin film membranes developed at IMM employ a silicon grid as support structure so that a high pressure resistance at a high permeability for Helium or Hydrogen can be provided respectively. Currently the membranes are applied in gas sensing applications but could also be used e.g. in the field of miniaturized reformer units and fuel cells. The geometry and membrane parameters could easily be adapted to other customer specific requirements.