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| Author(s): |
Marco César Prado Soares
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Mecânica |
| Defense date: | 2020-02-18 |
| Examining board members: |
Eric Fujiwara;
Marcos Akira D'Avila;
Cristiano Monteiro de Barros Cordeiro
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| Advisor: | Lucimara Gaziola de la Torre; Eric Fujiwara |
| Abstract | |
The design of two perfusion microfermentors which use membranes with pores of 470 nm and are instrumented with an optical fiber sensor based on reflectance and light scattering is presented. The design is modularized, with optoelectronic components physically separated from the detection region, and system fabricated only with commercial telecommunication devices (1310 nm laser, single-mode optical fibers, 2x1 coupler and photodetector). When light reaches the interface between the fiber and the fermentation broth, part of it is refracted and transmitted, and part is reflected back and redirected by the coupler to the photodetector. Due to the presence of particles with diameters comparable in order of magnitude to the laser wavelength, the phenomenon of the quasi-elastic light scattering is observed, and enhances the dispersion of the collected data. Through autocorrelation statistics of the reflected intensity, it is possible, then, to evaluate the instant concentration of cells. The fibers are allocated into the microchambers by two different strategies: insertion through a glass cover with holes, in a device fabricated by laser ablation of laminated PDMS; and lateral insertion into a device fabricated by the cure of PDMS on molds obtained by additive manufacture. Despite the fact that the second case results in lower dimensional deviations and in higher pressure supported, a significant increase on the fabrication and operation difficulties occurs, so the first case is preferable. The use of the first perfusion reactor with seven different substrate concentrations (2,5 to 30 g/L of sucrose) resulted in the Monod kinetic parameters KM = 4,1 g/L e ?m = 0,49 h-1, values that are in agreement with both the literature and the traditional control test (performed in parallel), with the presence of cellular growth inside the microdevices proven by optical microscope observation. The instrumented microfermentor consists, therefore, in a system adequate for the fast obtention of the cellular growth kinetic parameters (AU) | |
| FAPESP's process: | 17/20445-8 - Development of fiber optic sensor for reflectance and light scattering monitoring for microfluidics applied to biotechnology |
| Grantee: | Marco César Prado Soares |
| Support Opportunities: | Scholarships in Brazil - Master |