Strain and tilt measurement using multi-point diffraction strain sensor

A multi-point diffraction strain sensor (MDSS) was developed earlier by us for strain measurement with variable sensitivity and measurement range using a microlens array. The technique is now extended to measure both tilt and non-uniform strain with a sensitivity of 0.41 mε/pixel and 4.7 mrad/pixel. The validation was made through comparison of the strain measured using MDSS with that by a micro-Moiré interferometer incorporated with Gabor filtering method, while the tilt is compared with derivatives of the surface profile measured by a confocal microscope.