Resumen de Microfluidic platforms: from 3d printing to μpads for chemical and biological applications
Over the past decade, microfluidic technology has proven its capabilities to start bringing detection and quantification capacities to novel miniaturized devices. The current generation of microfluidic platforms provide great precision in detection and quantification. At the same time, they have started to evolve towards self-sufficient (stand-alone) setups. These platforms are relying less and less on external power sources and they use built-in detection and quantification methods to be flexible and mobile. Among the various Lab on a Chip (LOC) applications, micro–Total Analysis Systems (µTAS) and Point of Care Tests (POCT) are the pinnacles of microfluidic platforms. They are accurate, rapid, cost-effective, and user-friendly. They can monitor and measure compounds that were, previously, only detectable in state-of-the-art laboratories. This characteristic is quite important and vital, especially when it comes to human health status monitoring. Therefore, developing POCs and µTASs has been the center of attention for researchers in recent years.
To reduce the reliance of microfluidic platforms on external power sources and measuring instruments. There is the need to improve and enhance the microfluidic platforms, not only from the performance point-of-view but also from their manufacturability, to be able to batch produce them at lower costs.
Most microfluidic circuits detect or measure a compound and in the first step, they need to label/enhance a reaction, in other words, mix two or more components and then analyze the results based on the readout. This thesis proposes an enhancement of the performance of a key element in most µTAS and POC devices such as the micromixer, with the introduction of a geometrical expansion that increases the diffusion path without increasing the pressure loss. Afterwards, its performance is validated and the design has been used to quantify for the first time on a microfluidic platform the ionic strength of buffered and non-buffered solutions. Finally, and to avoid the need for syringe pumps, in the same quantification strategy, we have introduced paper as a substrate material and optimized the inlet geometry to enhance the performance of the novel microfluidic paper-diffusion-based sensor for ionic strength quantification. The proposed sensor was able to quantify the ionic strength of buffered and non-buffered solutions down to 0.1 M concentrations using Whatman 5 paper substrate.
