An electromagnetically-driven microfluidic platform with indirect-heating thermo-pneumatic valves

Abstract

In this work, we present a microfluidic platform which is capable of carrying out a series of laboratorial operations on a disposable chip. The platform employs coil arrays to transport biological samples attached on magnetic beads through different reaction zones in aqueous solutions. Micromachined thermopneumatic valves are adopted as the interfaces between sequential reactions. The self-contained system is composed of a disposable microfluidic reaction (MFR) chip and a fluidic driving/sensing (FDS) module. Various reaction zones with different functionalities are implemented on the MFR chip. Arrays of coils and micromachined heater/sensing chips are integrated into the FDS module. Also, novel indirect-heating thermo-pneumatic valves (IH-TPVs), which are monolithically integrated into the disposable MFR chip, are proposed and characterized. With an applied voltage of 3.2 V, the IH-TPV effectively isolates two adjacent reaction zones, while its temperature elevation is sufficiently low for biological samples and reagents. By employing the proposed approach, we design and implement a miniaturized biochip system which carries out the processes of DNA extraction, purification and amplification from whole blood sample. The dimension of the fully-integrated system is 72 mm×54 mm×11 mm, and the system could be fully operated with a 12 V DC power supply. DNA extraction and purification from human whole blood followed by PCR amplification for the 122 bp segment is successfully performed by using the system.

Combining Electro-Osmotic Flow and FTA® Paper for DNA Analysis on Microfluidic Devices

“…In order to overcome these challenges, there has been a move away from more traditional silica-based solid-phase extraction protocols to a range of innovative solutions. Magnetic beads, for example, can be used to capture nucleic acids or specific target cell types, which, once captured, can be manipulated around the microfluidic device, through different reagents, by an external magnet [ 7 , 8 ]. Alternatively, the magnetic beads can be retained within a single chamber and the different reagent solutions flowed over the reversibly immobilised solid phase [ 9 ].…”

Microdispositivo giratório de poliéster para integração de preparo de amostra e reação de amplificação para análises genéticas

“…144 Válvulas controladas pelo aquecimento ou resfriamento também foram muito utilizadas. 146 Amasia e colaboradores (2012) 145 demonstraram uma válvula baseada no congelamento de uma solução dentro de canais que interligam diferentes câmaras e assim interrompem o fluxo do fluido. Outra metodologia muito utilizada é a ativação das válvulas utilizando um laser.…”