Technology Overview

This invention describes a first-of-its-kind microfluidic system that takes advantage of the unique properties of yield-stress fluids to generate droplets in the form of crystallised particles. In the system, nozzles inject fluid into a yield-stress bath—complex materials with solid-like and liquid-like behaviour—and form droplets embedded within. Conveniently, these injections may be automated and scheduled according to set timings, forming the desired droplets when needed.

Contrary to traditional microfluidic approach, this system no longer requires convection forces to drive fluid flow. Instead, the immiscibility of the injected fluid and yield-stress bath allows the precise formation of small, suspended droplets that are perfectly spherical. Moreover, the bath material prevents the environmental contamination or evaporation of the droplets.

Given the isolated state of the droplets, unwanted mixing is prevented and complex experimental set-ups can be carried out with ease. For instance, a certain droplet can be allowed to develop undisturbed for a longer period of time or reagents added and removed without disturbing other droplets. By eliminating the effects of external forces, this invention enables droplet processing at a level of precision difficult to achieve with traditional microfluidic systems.

Technology Features, Specifications and Advantages

An apparatus for forming one or more compartments, including:

• a nozzle including an outlet, the outlet for introducing one or more volumes;
• a yield-stress fluid, the yield-stress fluid in contact with the outlet of the nozzle; and
• a controller configured to displace the nozzle and/or the yield-stress fluid relative to each other to introduce one or more volumes into the yield-stress fluid to thereby form one or more compartments from the one or more volumes.

A method for forming one or more compartments in a yield-stress fluid, including:

• introducing one or more volumes from an outlet of a nozzle into a yield-stress fluid, the outlet of the nozzle being in contact with the yield-stress fluid; and
• displacing the nozzle and/or the yield-stress fluid relative to each other to thereby form one or more compartments in the yield-stress fluid, the one or more compartments being formed by, or formable from, the one or more volumes.

Potential Applications

Much like miniaturised laboratories, microfluidic devices offer a compact environment for processing fluids through small channels—resulting in increased precision, faster chemical reaction rates and reduced reagent costs. Given these advantages, the microfluidics global market size was valued at US$12.8 billion in 2019 and is expected to grow to US$66.6 billion by 2027.

In the pharmaceutical industry, droplet-based microfluidics are used to produce microcrystals and polymer particles that make up drug products. Since crystal structure largely affects the functionality of pharmaceutical products, a highly regulated, well-controlled setup is important for manipulating each droplet and producing the desired particles.

While microfluidics offers greater control over droplet volume and composition, crystal formation can still be unpredictable. The tubing channels typically require solid boundaries and continuous flow, leading to difficulties in controlling droplet’s flow as well as deformations. External convective forces may also cause the unwanted combining of droplets, resulting in particles fouling or clogging the microchannels. To ensure proper crystal formation, there is a need to explore new microfluidics approaches that address the aforementioned limitations.

Customer Benefit

Provides spatial and temporal precision in manipulating fluids

Highly regulated delivery via nozzles that release fluids following a predetermined schedule and volume

Immiscibility of yield-stress bath protects embedded droplets against environmental contamination and unwanted mixing

Achieves perfectly spherical droplets by removing external influences like convective forces and solid boundaries

Isolated state of embedded droplets allows experimental manipulation without disturbing individual droplets

Diverse applications including the crystallisation of uniform drug particles for pharmaceutical products drug manufacturing, bioassays and even diagnostics, among others