Characterization of microstructures with in-line digital micro-holo-interferometry

With respect to the two major challenges in micromeasurement, which are high resolution and small object size, digital micro-holo-interferometry is proposed in this paper to provide quantitative information on load-induced variations of microstructures under testing. As primarily measured properties, the obtained deflection-load relationship enables subsequent accurate determination of strain and stress. More importantly, properties of materials in the micro level, which are known different greatly from those of identical bulky ones, can be evaluated based on these experimental input data for computational simulations. Developed upon the in-line configuration and incorporated with long distance microscope, the proposed system can achieve higher imaging performance and resolution capacity. Studies demonstrate that it is capable of realizing accurate measurement to microstructures with lateral dimensions of at least 8 microns. Its applications in characterization of microstructures are experimentally investigated on a micro cantilevered beam as an example. The load-induced deflection is obtained and validated with numerical simulated results based on finite element analysis.