Strain measurement of foil material in micro-machining based on computer vision

Micro-machining plays an important role in MEMS. In the micro-machining, the influences of the surface effect and the size effect must be considered. Moreover, the deformation and damage mechanics of the materials of the micro parts are different from those of the macro ones. Thus, traditional measuring methods are unsuitable for the micro-machining. In this paper, a new apparatus based on the computer vision is developed to measure the micro tensile strain of foil material in the micro-machining. A three-CCD computer vision system is constructed. Through image processing and calculation the micro-strain of the specimen is obtained. Therefore, on-line measurement of the micro-strain in the micro-machining can be realized by this system.