This study presents a novel polyimide-based self-assembly three dimensional micro blade using surface micromachining technology for the development of micro-fan chip. The high surface-tension-force of reflowed polyimide has can be used to lift the free-standing micro blade. In addition, the thesis introduces a micro hinge structure to effectively limit the maximum lifting angle of the micro blade and to accurately lock hinge-pin into the vertical position. Many parameters have been investigated its influence on the surface-tension- force of polyimide, including the thickness of polyimide and the temperature/time in reflow processing. Based on the experimental results, 18 £gm-thick polyimide can lift the micro blade at 70¢X angle under 380 ¢J/10 hrs reflow condition. On the other hand, 25 £gm-thick polyimide has demonstrated its maximum lifting angle can be achieved to 130¢X utilizing the very high surface-tension-force induced by over contraction and deformation when it was reflowed at higher temperature (400 ¢J). Finally, this dissertation has studied the relation between the position of polyimide elastic-joint and the deflection angle (£r). Furthermore, this thesis has successfully demonstrated a novel multi-joint and asymmetrical microstructure for the development of the spiral and out-of-plane 3D micro blade.