Preparativa de muestra microfluídica para labonachips de su8

Abstract

ABSTRACT This thesis develops a two chamber microfluidic device, Labonachip, for clinical diagnostic applications. An electrolytic micropump and a burst microvalve for one-use were designed, fabricated and characterized in SU8, the structural polymer selected for the microchip. The optimization of fabrication parameters of the SU8 polymer and the elements design (pump, valve, chambers, electrodes, sensors) allows his integration in one microchip, with the maximum efficiency and simplicity for the analytic steps in a complete analysis with real sample, from sample preparation to specific detection by PCR. This device performs DNA concentration with magnetic particles in a sample preparation chamber. In this chamber takes place the purification, allowing work with high volumes of solution. Next, the drain outlet closes and the concentrated DNA moves to the DNA amplification chamber. Every time, the DNA is contained inside the microchip, avoiding cross-contamination. The electrolytic micropump shows pressure for moving the liquid between two chambers; even achieve 4 atm of pressure. In the other part, the SU8 one-use burst valve bases his design in a narrow structure (30 µm), high (300 µm), anchorages in the top and the bottom, without deformations or leakages. The equilibrium of the fabrication parameters of the SU8 is achieved. The burst valve is included in two designs, circular and hexagonal. The obtained results show high pressures valves (circular valves) and low pressure valves (hexagonal valves). The latest is integrated in the final microchip design. In this thesis, the microfluidic validity of the labonachip is checked for the integration of the electrolytic micropump and the burst valve. Through the test with DNA sample, the nucleic acid is concentrated, purified and moved between the two chambers showing the viability of the labonachip for clinic applications. The work of the thesis shows a new strategic for real sample analytic, included the sample preparation and DNA amplification in a disposable labonachip with integrated actuators. The characteristics of the developed device reduce the manipulation from the users and the cross-contamination of the test, at the same time that simplifies the analysis.