Full text
| |
| Author(s): |
Merilyn Santos Ferreira
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Escola Politécnica (EP/BC) |
| Defense date: | 2014-01-28 |
| Examining board members: |
Eduardo Acedo Barbosa;
Marcos Roberto da Rocha Gesualdi;
Sebastião Gomes dos Santos Filho
|
| Advisor: | Eduardo Acedo Barbosa |
| Abstract | |
The aim of this work is to apply photorefractive crystals holography technique for the study of mechanical properties of micro-devices; it ensures obtaining a simple and compact geometry of holographic setup. Vibration and deformation analyses of micro-devices were performed using time average and double exposure interferometry, respectively. As light sources, it was used diode lasers emitting at 660nm, and He-Ne laser emitting at 632.8nm. As photorefractive holographic recording medium was used Bi12TiO20 (BTO) crystal, family of selenites. An optical setup of Denisiuk-type reflection holography was proposed, and this setup was added a set of objective and eyepiece lenses to form a compound microscope configuration, in order to obtain holographic images of objects with microscopic dimensions. Recording and reconstruction of the hologram occurred simultaneously, due to the combination of the photorefractive crystal to a CMOS camera. Thus, holograms observation occurs in real time. It was initially performed double exposure images of MEMS (microelectromechanical systems) piezoresistors, with reduced geometry (2.96 x 0.6 mm2), and CMUT (capacitive micromachined ultrasonic transducers) devices with 640m diameter. By this technique was possible measure displacements of 0.33m to 4.3m. Time average interferograms of Ceramics and piezoelectric transducers were also obtained, however, it illuminating only small regions of these objects. These images showed reasonable quality, indicating that it is possible apply the time average technique for objects with vibration amplitude between 0.12m e 1.7m. In order to investigate the microscopic potentialities images of resolution test chart were done, where it was possible to visualize structures with geometries between 20 m and 2mm. (AU) | |
| FAPESP's process: | 11/03933-2 - Holographic and holographic interferometry with diode lasers for the characterization of capacitive micro-transducers |
| Grantee: | Merilyn Santos Ferreira |
| Support Opportunities: | Scholarships in Brazil - Master |