The aim of the project is the development of a new technology for the fabrication of bismuth (Bi) micro-nano Hall sensors integrated on plastic cantilevers. Bi, a semi-metal, is deposited by evaporation and structured by lift-off. Four electrodes made with Ti-Al are deposited and structured in the same way as Bi. SU-8 cantilevers and carrier chip are structured by photolithography process. The smallest size of the Hall sensor active area obtained with the photolithography was 2 x 2 um2 and was reduced to the nanometer scale (200x200 nm2) by the mean of the focused ion beam (FIB).