Highlights 10  Modifying electrical contacts by electropolymerization of MMA is studied. 11  Ten times increase in the corrosion resistance of electrical contacts is observed. 12  The electrical resistance increased, but remained well below the accepted limit. 13  Cathodic electrodeposition of PMMA effectively sealed the pores of Au top-layer. Abstract 16 Cu/Ni-P/Au multi-layer systems are employed as electrical contacts. The Au top-layer is thin and 17 porous. These pores deliver the corrosive media to the under-layer, which induces the corrosion 18 by a galvanic coupling mechanism. Therefore, filling these pores is essential to improve the 19 lifetime of electronic devices. The pores can be sealed by the electrodeposition of poly(methyl 20 methacrylate) that decreased the porosity index (about 97%) and increased the corrosion resistance 21 (about 10 times) of electrical contacts after 10 cycles of electropolymerization. A non-uniform 22 polymeric film, however, was formed at higher number of polymerization cycles (> 50) that 23 decreased the corrosion resistance. 24