Portable. Inexpensive. Revolutionary. What do these 3 words have in common? They are the characteristics of microfluidic-based devices.
But what is microfluidics? And how is it connected with diagnostics? In the process of treating and curing diseases, diagnosis is the initial step that helps identify the cause and status of a disease.
Point-of-care testing (POC), a diagnostic testing performed at the patient’s convenience, has been advocated for by the National Institutes of Health (NIH) to bring about a “paradigm shift from curative to predictive, personalised and pre-emptive medicine” .
This is where microfluidic-based systems come into play.
Microfluidics is a science and technology that describes and manipulates the behaviour of fluids at a scale that is one hundredth the thickness of a human hair. If you cannot visualise that, try looking at your credit card’s thickness. Now divide that 1000 times and you’d reach the micron scale.
Microfluidics has found applications in various areas, especially biomedical applications, such as cancer diagnosis, pregnancy testing, HIV diagnosis, glucose biosensors, and drug administering . Despite being considered only in its “infancy,” microfluidics has the potential to become a widespread, cutting-edge technology with remarkable features in the near future.
So, why is that? Here are 3 reasons why microfluidic-based systems will effectively become common devices employed in almost every field that requires the manipulation of fluids, in particular, diagnostics.
Microfluidic systems are efficient and reliable
Microfluidic devices are palm-sized devices (or chips) encompassing intricate microscale circuits and channels, connected via little tubings, and inside of which fluid samples are circulated. Let me paraphrase that. Microfluidics allows for the fabrication of millions of microchannels that would perform several operations, on a single chip that fits in your hand!
Depending on the purpose and application of the device, channel geometries and designs are customised, and the systems are often integrated with other detection technologies to bring about prompt analyses and effective results, all while sampling tiny amounts of fluids and reagents.
- the ease of customisation and manufacture,
- the type of materials used for production,
- the ability to accurately and precisely manipulate the (bio)particles flowing in the introduced fluid samples,
microfluidic devices can demonstrate exceptional efficiency and quality, providing consistent, effective results with insignificant percentage error .
In addition to that, the process time, compared to traditional methods of diagnosis, is cut from hours, and even days, down to minutes.
Microfluidics are convenient and portable
The miniature, compact configuration of microfluidic devices (also commonly known as Lab-on-Chip (LOC) devices, which represent the combination of several laboratory processes on a single chip) demonstrates a substantial advantage in terms of portability, accessibility, and ease-of-use.
Patients in their own homes can make use of LOCs for monitoring and assessing certain aspects of their health, such as checking electrolytes during diuretic therapy and observing serum creatinine and blood urea nitrogen levels if suffering from chronic kidney disease .
This can even diminish the necessity of trained personnel. Venture capitalist Vinod Kholsa, in his article for TechCrunch, predicted that an integration between future diagnostic devices and state-of-the-art algorithms could take the place of 80% of doctors . Crazy as it might sound, given the trend of growth that healthcare is taking, the future of such diagnostic devices is very promising.
In addition to that, LOCs have successfully provided rapid diagnosis of infectious diseases such as HIV, tuberculosis, hepatitis, and malaria . This could offer considerable benefits for patients in developing countries and areas with few resources.
Microfluidics are cost-effective
On top of its high efficiency and convenience, microfluidics offers the essential benefit of low cost of production per device compared to other technologies. Not only is this effective for production, but it also allows for disposability .
An example of this is a microfluidic device expected by scientists to be realised in the near future that can produce quantitative results in under 1 minute, while using as low as 1 microliter of sample volume, costing less than $1 to be mass manufactured .
The two main reasons for this cost-effectiveness are the materials used to fabricate microfluidic devices and the methods of production.
I’ll focus on the materials here. Selection of such materials relies on the application for which the device is being manufactured.
Silicon is one of the primary materials used in microfluidics. It is a characteristic material due to its thermal conductivity, compatibility with solvents, and surface stability. Yet, its opacity makes it difficult to perform optical detection.
Glass is another effective material whose features exceed those of silicon with the addition of transparency, high-pressure resistance, biocompatibility, and hydrophilicity. Its drawback, however, lies in its relatively higher cost.
Polymers – most commonly polydimethylsiloxane (PDMS) – are extensively used as fabrication material. PDMS is cheap, transparent, elastic, and permeable to gas, which is good for cell cultures and processing. Despite its shortcomings, such as aging and poor chemical compatibility with certain organic solvents, PDMS is still widely used in microfluidics.
Polystyrene (PS), polymethylmethacrylate (PMMA) and polycarbonate (PC) are other polymers also used for fabrication of microfluidic devices.
Another material showing strong potential for the fabrication of microfluidic chips is paper. This potential is characterised by its inexpensiveness, lightweight, thinness, biocompatibility, disposability, and ease of storage and manipulation. However, it still shows difficulty in channel patterning on the chip.
Hydrogels are also prospects for microfluidic devices due to their malleability, biocompatibility, commercial availability, non-toxicity, and low cost .
Are microfluidics the future?
Portable. Inexpensive. Revolutionary. Yes, the future of microfluidics in the field of medical diagnostics is very promising and opens up a world of exciting opportunities to dive into.
Which of those reasons do you think would be the most valuable in ensuring that future? Or did I not mention something you believe could be as valuable?
Either way, let me know by leaving a comment below right now.
 Gomez, F. (2013). The future of microfluidic point-of-care diagnostic devices. Bioanalysis. 5(1). 1-3
 Minnella, W. (2013) Microfluidics and its applications: a short review.
 Sonmez. U., Jaber, S. and Trabzon, L. (2017). Super-enhanced particle focusing in a novel microchannel geometry using inertial microfluidics. J. Micromech. Microeng. 27 065003.
 Komatireddy, R. and Topol, E. (2012). Medicine Unplugged: The Future of Laboratory Medicine. Clinical Chemistry. 58:12. 1644-1647.
 Khosla, V. (2012) Do we need doctors or algorithms?
 Schulze, H. et al. (2009). Multiplexed optical pathogen detection with lab-on-a-chip devices. J. Biophotonics. 2(4). 199-211.
 Gervais, L. et al. (2011). Microfluidic Chips for Point-of-Care Immunodiagnostics. Adv. Mater. 23. H151-H176.