Mayra Yucely BEB CAAL : "complete 3D surface reconstruction with the scanning electron microscope for metrological and educational applications"

Abstract : This thesis addresses the challenge of 3D surface reconstruction using scanning electron microscopy. Scanning electron microscopes find extensive applications in various fields, including engineering, biology, and geology. However, they inherently provide only 2D images. This thesis proposes a method for comprehensive 3D reconstruction, divided into two phases, of the surface of individual microscopic specimens observed through this microscope. In the initial phase, high-quality partial reconstructions are generated from approximately one hundred images obtained by rotating the specimen 360°. The geometric reconstruction approach with precise autocalibration, previously developed in the laboratory (Pollen 3D), is employed. In the subsequent phase, the partial reconstructions are aligned using the ICP algorithm and then integrated to construct a 3D point cloud, which is further converted into a mesh suitable for printing. Alongside the 3D reconstruction process, protocols for sample handling within the vacuum chamber are defined, laws controlling centering and autofocus are developed for capturing input images, and methods for filtering 2D images and cleaning point clouds are devised. The developed methodologies were validated using Zeiss and Thermofisher microscopes across various specimens, including pollen grains, turning tools, a foraminifer, and a shark tooth. These reconstructions hold potential utility in educational contexts, preservation efforts for delicate samples, and metrological applications.

Jury Composition : 

M. Sounkalo DEMBELE Associate Professor Université Bourgogne Franche-Comté,  Directeur de thèse
M. Sinan HALIYO Associate Professor Sorbonne Université, Rapporteur
M. Olivier HAEBERLE Full professor Université de Haute-Alsace, Rapporteur
Mme Nadine PIAT Full professor Université Bourgogne Franche-Comté, Co-directrice de thèse
M. Sébastien THIBAUD Full professor Université Bourgogne Franche-Comté, Co-directeur de thèse
Mme Karine MASENELLI-VARLOT Full professor INSA, Lyon Examinatrice
Mme Isabelle JOUFFROY-BAPICOT, Ingénieure de recherche, Université Bourgogne Franche-Comté Examinatrice
M. Rainer TUTSCH Full professor Technische Universität Braunschweig Examinateur

Localization : Amphi Jules Haag, SUPMICROTECH-ENSMM - 26, Rue de l'Epitaphe -25000 Besançon