Sensor integration and integrated flow control within microfluidic PoC devices

Sensor integration and integrated flow control within microfluidic PoC devices Background: This master thesis presents the work and the experiments performed at Micronit micro technologies in the framework of the KardiaTool project. Micronit is a company headquartered in Enschede, Netherlands, specialized in the design, development and production of state-of-the-art devices for microfluidics and MEMS applications. The company offers a wide range of services and products, such as organ-on-chip, microreactors and micromixers design, development, prototyping and manufacturing. The aim of the KardiaTool project is to integrate the concept of saliva biosensing into clinical practicing for addressing the medical needs in personalized heart failure diagnosis and therapy monitoring at point of care. The KardiaTool platform will be a complex system, incorporating mechanical, electrical and microfluidic subsystems and the different interfaces that link them. The main innovation presented by KardiaTool consists in the incorporation of four saliva biomarkers already proven in laboratory setting into a device that will be used at the point of care and will be accessible to different medical structures and usable by medical professionals. The different biomarkers will be sensed through the magnetic sensing of functionalized magnetic nanoparticles. The choice of saliva as source of biomarkers is forecasted to be beneficial for the healthcare community due to being cost effective, non-invasive, more convenient and acceptable for both patient and healthcare operators in comparison to more common biological matrix like blood. Objectives: This thesis will report the work performed on two different aspects of the KardiaTool platform: The first part of the working process was focused on the integration of the silicon chip for sensing into a polymeric cartridge through hybrid bonding; the second part was focused on the design, fabrication and characterization of the microfluidic polymeric cartridge present in the Lab-on-chip part of the device. Methods: For the sensor integration part of the work four different glues were testes and dispensed on polymeric dummy chips prepared for the occasion. The parameters affecting the dispensing process were optimized until a homogeneous deposition of glue was obtained. The chips were then bonded with glass slides and the quality of the bonding was assessed. For the polymeric chip cartridge characterization, the polymeric valves and the polymeric channels were characterized. The liquid flow rate and stability of the different batch of chips were measured, and the quality and the behaviour of the valve was observed through fluorescence microscopy. The complete working routine of the chip was tested, and the sequence optimized. Conclusions: Regarding the sensor integration, the obtained results were positive, and it was demonstrated to be possible to dispense precisely different kind of glue in order to obtain a uniform, hermetic bonding between a silicon chip and the polymeric cartridge. Set of optimized parameters for an optimal bonding were obtained. Regarding the chip characterization, the behaviour of different batches of chips was analysed and the design and the fabrication of the sample was improved through the internship, ending with a functioning prototype for future experiments.