What is the resistance of Si cantilever without coating?
The specific resistance of Si is 0.01-0.05 Ohm*cm. However, in air, silicon always has a native oxide layer, which is not conductive. You can try to remove it in UHV and use cantilevers in UHV immediately, because in air the native SiO layer will grow again very soon. You can also purchase cantilevers with conductive coating like Ti-Pt.