Abstract
Micro springs of Ni was fabricated by UV-LIGA(UV-lithography and electroforming) process. The spring was S-shaped and was 1 mm high, 0.85 mm wide and 50 μm thick. For the purpose of detecting the spring characteristics and fatigue strength, new testing machine was developed as a microfactory cell. This system is characterized by its static and dynamic, repeated loading mechanism. A moving coil electromagnetic linear motor is used as a loading mechanism, and the load is calculated by the current of the coil that is supported by a parallel plate spring structure. The displacement of the moving coil is measured with a linear differential transformer installed in the loading unit. Using this apparatus, we measured the spring characteristics and confirmed good agreement between the experimental and FEM-designed characteristics of the spring. The fatigue tests were carried out on the microsprings. As a result, this test system is useful for investigating fatigue strength and detecting microstructural changes.
