In this project we develop hydrogen sensors based on nanoscaled discontinuities (nanogaps) in palladium (Pb). These nanogaps reversibly close and open upon hydrogen/air cycling due to an increased lattice constant in the hydrated state. Therewith, an electrical current can be switched. We investigate various technologies to realize nanogap based device such as FIB milling, electrodeposition and srtandard evaporation and lift-off techniques. The sensing characteristics of single gaps and gaps arranged in percolating networks are assessed.