Obtaining low temperature crystallised NiTi films would ensure a good compatibility with microelectronics processes and allow deposition on substrates that could not endure high temperatures, like polymers. We found that NiTi films containing an excess of Ti (52% at.) are crystallised when deposited on Si(100) substrates heated up to only 200 o C. Resistance vs. temperature measurements show typical martensitic transformation behaviour. By depositing this type of films on polyimide substrates, we obtain bimorph micro-actuators exhibiting a two-way shape memory effect.