Microfluidics’ ability to perform chemical analyses of small volumes of fluids have reduced hospital visits and overall healthcare expenditures. And, their use is rising rapidly.
In previous articles, we covered the basics of microfluidics and also discussed the four key materials when it comes to building microfluidic devices. In this blog post, we’ll focus specifically on how microfluidic fabrication technology — miniaturized laboratory or lab-on-chip (LoC) — allows for many diagnostic applications that make a big impact on medical care.
Reliability and Consistency are Imperative
Microfluidic devices have powerful diagnostic abilities, specifically a test kit for infectious disease detection. We’ve all heard tales about COVID-19 tests resulting in “false positives” and the impact these results have on the lives of patients, their families, and the community. So, more than ever, having reliable diagnostics tools helps control the spread of infectious diseases, provides timely treatment, and helps better manage patients.
Part of making a microfluidic device reliable is precision die cutting to ensure the device functions properly. An LoC is made of molded plastics or laminates and is usually produced in large quantities, which makes the diagnostic testing low-cost and high throughput. Within it, fluid needs to flow in a specific way and precisely combine with different materials to get accurate results.
Of course, the usefulness of microfluidic cartridges extends far beyond diagnosing the coronavirus. Many point-of-care (PoC) applications are used to diagnose more common health issues, from blood sugar and blood pressure tests to diabetic strips. They all rely on the speed, ease of use, low cost, and reliability of microfluidic devices.
The Challenge of Creating Millions of Microfluidic Devices
Moving fluids within a microfluidic device requires specific surface energy materials, specific material thickness, and very specific width channels to be cut in these materials. This is work that must nail high tolerances. Any variation means the fluid doesn’t flow at the correct speed or doesn’t flow at all.
Early in the development of an LoC microfluidic cartridge, assembly may be done by hand. However, when volume increases, the only way to accurately apply layer upon layer of material in quantities in the millions is to use automation that’s designed for manufacturability (DFM). Meeting specific functional requirements in huge quantities means a converter must develop the exact right manufacturing process.
The “micro” part of microfluidics means that a device may have features that require laser cutting instead of traditional hard tooling. For instance, imagine a part with 14 layers, each with its own complex shape, that must be cut precisely and then placed upon another 6-layer stack with every layer requiring a tight tolerance die cut, some within one-half of a millimeter. Only automation (a robot with a camera eye) can pull this off.
Constructing a Microfluidic Device
With design for manufacturability in mind, and knowing that millions of microfluidic devices will need to be manufactured, what are the biggest challenges in developing practical PoC diagnostic tools?
The first may be selecting materials in the construction of a device that meet various parameters as far as size and weight. On a related note, oftentimes a device’s reagent media is part of the construction process, requiring certain environmental factors to exist during manufacturing: keeping a steady temperature and humidity level as well as minimizing light that may cause the reagent to degrade.
A fully controlled environment — a cleanroom with controlled temperature/humidity and monitored air particles — is mandatory when creating nearly any medical device, including microfluidics. And adhesives must be selected specifically to be used near fluids; hydrophilic, hydrophobic, etc.
From a converter’s perspective, a microfluidic chip can be seen as a complex, channelled, multi-stacked, flexible material on a roll that can be automatically dispensed and automatically packaged. Tight tolerance die cut components need to be scalable to be successful.
Faster Diagnosis. Faster Treatment. Faster Production.
Anyone who’s sick wants a quick, accurate diagnosis and treatment as soon as possible. Microfluidic devices are increasingly becoming labs-on-chips (or LoC), being able to perform multiple tests on a single, amplified sample; even going as far as breaking up DNA chains to determine future health-related tendencies.
With advancements happening at such a rapid pace, the challenge for converters is to be able to design and build microfluidic devices for high-speed manufacturing. Of course, ensuring each is reliable and all are consistent. Currently, the number of U.S. converters ready for this level of manufacturing can be counted on one hand.
It’s easy to see why partnering with a full service adhesive tape converter that fully understands microfluidic fabrication technology is a wise move. If you need any help with developing a diagnostic application device, give Strouse a call today (800)-410-8273 or you can ask an engineer about adhesive solutions today!