Executive Summary:

Genome sequencing has become one of the most important biomedical applications in recent years as worldwide pandemic strikes. Since conducting genome sequencing for such viruses is one of the most useful and straightforward methods of figuring out the source and behavior of these viruses to protect humans, biomedical companies and laboratories around the world have been trying to improve the current method of sequencing. The sponsor of this project, Illumina, is one of the cutting edge biotech companies across the world that is able to conduct genome sequencing onsite or by request for research purposes. Besides onsite operations, Illumina is also providing sequencing machines and cartridges in the market for those who want to conduct genome sequencing at their convenience. Shipping is an important issue for cartridges where the reagents needed for sequencing that come with the cartridge is perishable, this means Illumina has to ship the reagent with a large amount of dry ice to keep its integration during shipping progress. This greatly increased shipping cost and thus entire product cost. Illumina has implemented a substitution shipping method to reduce shipping cost. Instead of ship reagents with dry ice, Illumina dehydrates reagents before shipping and asks customers to rehydrate reagents onsite before conducting any tests. Such a method will inevitably involve mixing multiple reagents with buffers during rehydration, and this project is aiming to optimize the current mixing method Illumina is using. 

The mixing strategy Illumina currently is using is to implement a sipper connected to a syringe by tubing that is controlled by a syringe pump. The syringe pump will thus aspirate and dispense fluid from and into the well automatically according to a predetermined recipe. The purpose of this project is to revise this method by applying changes to the system, including the syringe pump, tubing, sipper and reagent well. 

As discussed by the team, the availability for modification has been limited into the sipper design. As the objective of this project is to revise the current mixing method, it would be inappropriate to change the original structures provided by the sponsor. Changing the sipper design would be the most plausible design approach by comparison in table 2. 

The team proposed several possible designs, such as “shower head” nozzle, jet nozzle, and the fluidic plate. Each has been put into CFD analysis and physical testing, the result shows that T-Nozzle performs the best by out performing other nozzles by 62.66% of coefficient of variation. Furthermore, the proposition of implementing a tesla valve also brought another option for the team. Unfortunately the testing result for tesla valve does not show a promising change in the performance of mixing. Instead, the team has decided to use a check valve, which serves the same purpose, and assemble two check valves together to achieve a system that can aspirate fluid from the bottom of the well and dispense at the surface level of the fluid in the well along with the nozzles designed. The new system that circulates fluid inside the well achieved a 143.55 % lower coefficient of variation (a measure of inhomogeneity) than control nozzle, which accomplished the project’s optimization goal.