Investigating the mechanotransduction of transient shear stress mediated by Piezo1 ion channel using a 3D printed dynamic gravity pump

Microfluidic systems are widely used for studying the mechanotransduction of flow-induced shear stress in mechanosensitive cells. However, these studies are generally performed under constant flow rates, mainly, due to the...

Orientation of Liquid Crystalline Molecules on PDMS Surfaces and within PDMS Microfluidic Systems

The unique components of PDMS-based microfluidic systems are those combined with liquid crystalline materials. Their functionality, especially when it comes to optical applications, highly depends on the LC molecular arrangement. This work summarizes experimental investigations on the orientation of molecules within LC:PDMS structures according to the manufacturing technologies. The availability of high-quality molds to pattern PDMS is a significant barrier to the creation of advanced microfluidic systems. The possibility of using inexpensive molds in the rapid and reproducible fabrication process has been particularly examined as an alternative to photolithography. Different geometries, including an innovative approach for the electrical control of the molecular arrangement within PDMS microchannels, are presented. These studies are critical for novel optofluidic systems, introducing further research on LC:PDMS waveguiding structures.

The Development of a Low-Cost Microfluidic Magnetic Separation System

<p>Microfluidic systems show excellent promise for analytical applications, due to their ability to rapidly process minute sample quantities with high sensitivity. At the same time, functionalised superparamagnetic magnetic microbeads and nanoparticles have emerged as useful substrates for biomedical applications such as bioassays, fuelling research into tools for the manipulation of magnetic particles in microfluidic channels. This thesis describes the design, fabrication and evaluation of microfluidic systems for the separation of magnetic microbeads and nanoparticles. Microfluidic devices were produced in polydimethylsiloxane using a low-cost rapid prototyping process. Channels 300μm or greater in width were accurately reproduced using this method. Laminar flow was observed in the channels of these devices, allowing two-phase flow to be used for separation purposes. Magnetic field gradients of 25-500 T/m were generated in the microchannels using either permanent magnets or soft magnetic materials. The performance of a permanent magnet-based separation system was evaluated, and it was found that the system could extract magnetic microbeads with an efficiency of up to 75%. A limited ability to separate magnetic microbeads on the basis of magnetic moment and/or particle size was also demonstrated.</p>

The Development of a Low-Cost Microfluidic Magnetic Separation System

<p>Microfluidic systems show excellent promise for analytical applications, due to their ability to rapidly process minute sample quantities with high sensitivity. At the same time, functionalised superparamagnetic magnetic microbeads and nanoparticles have emerged as useful substrates for biomedical applications such as bioassays, fuelling research into tools for the manipulation of magnetic particles in microfluidic channels. This thesis describes the design, fabrication and evaluation of microfluidic systems for the separation of magnetic microbeads and nanoparticles. Microfluidic devices were produced in polydimethylsiloxane using a low-cost rapid prototyping process. Channels 300μm or greater in width were accurately reproduced using this method. Laminar flow was observed in the channels of these devices, allowing two-phase flow to be used for separation purposes. Magnetic field gradients of 25-500 T/m were generated in the microchannels using either permanent magnets or soft magnetic materials. The performance of a permanent magnet-based separation system was evaluated, and it was found that the system could extract magnetic microbeads with an efficiency of up to 75%. A limited ability to separate magnetic microbeads on the basis of magnetic moment and/or particle size was also demonstrated.</p>

Microfluidic Systems for Cancer Diagnosis and Applications

Microfluidic devices have led to novel biological advances through the improvement of micro systems that can mimic and measure. Microsystems easily handle sub-microliter volumes, obviously with guidance presumably through laminated fluid flows. Microfluidic systems have production methods that do not need expert engineering, away from a centralized laboratory, and can implement basic and point of care analysis, and this has attracted attention to their widespread dissemination and adaptation to specific biological issues. The general use of microfluidic tools in clinical settings can be seen in pregnancy tests and diabetic control, but recently microfluidic platforms have become a key novel technology for cancer diagnostics. Cancer is a heterogeneous group of diseases that needs a multimodal paradigm to diagnose, manage, and treat. Using advanced technologies can enable this, providing better diagnosis and treatment for cancer patients. Microfluidic tools have evolved as a promising tool in the field of cancer such as detection of a single cancer cell, liquid biopsy, drug screening modeling angiogenesis, and metastasis detection. This review summarizes the need for the low-abundant blood and serum cancer diagnosis with microfluidic tools and the progress that has been followed to develop integrated microfluidic platforms for this application in the last few years.