What is Microfluidics?

What is Microfluidics?

Microfluidics is the science and technology of directing, analyzing, and testing fluids by way of microchannels created in a chip.

Generally, manufacturers make these chips from glass, silicon, paper, ceramic, or polymers; however, a recent addition is a silicone rubber called PDMS (Poly-Di-Methyl-Siloxane).

In terms of operation, the system first feeds liquids into input ports. Next, it pumps them around microchannels and into microchambers. Afterward, it mixes and senses them before finally extracting the results via output ports.

To give an idea of the scales involved:-

• Typical chip sizes are from 1 – 10 cm, with thicknesses of 0.5 – 5 mm.
• The channels are a few micrometers (10^-6m) to a few millimeters (10^-3m) in width.
• The fluid quantities are on the micro-liter, nano-liter or even the femto-liter scale.
• Pumps move fluids at a rate of 1 – 10,000 microliters/minute.

These dimensions bring very different characteristics to fluid mechanics from what we normally see on the macro-scale.

What are the Benefits of Microfluidics?

The main benefits are to allow rapid experimentation on tiny quantities of fluids such as blood, reagents or cancer cells in a repeatable and automated manner.

Some fluids can be scarce or difficult to source or simply need to be analyzed in-situ in remote locations.

The small dimensions and small quantities of fluids involved allow for more precision in lab analyses as well as more cost-effective and faster results.

On-chip sensors allow for data interfacing to automate processes, and connection to AI tools for data analysis.

Where is Microfluidics Used?

The sectors where we can find Microfluidics include:-

• Biotechnology
• Pharmaceuticals
• Nanotechnology-based Energy products
• Chemicals
• Industrials
• Cosmetics
• Nutraceuticals / Food
• Medical

Examples include:

• drug encapsulation
• drug delivery
• cell analysis & diagnosis
• trapping cancer cells in blood
• molecular and cell biology research
• genetics
• Lab on a Chip
• Organ on a Chip
• fertility testing and assistance
• synthesis of chemicals or proteins

How are Microfluidics Chips made?

This depends on what materials are used to fabricate the chip.

There are 4 main techniques:

• Etching (wet or dry)
• Thermoforming (embossing, injection molding)
• Direct writing (micro machines, lasers)
• Polymer casting (soft lithography)

When we decrease the width of the channels, we increase the ratio of surface area to volume. This allows us to capture cells, germs and nanoparticles more easily.

The devices can also serve as sensors using magnetic or electric fields, which are more effective at shorter distances.

Are Microfluidic Chips a type of Smart Glass?

We think so, since our definition of smart glass is not limited to just ‘switchable glass’ :-

We define smart glass as ‘any glazing material having surface coatings, internal structures or embedded circuits that influence the optical, electrical, thermal or mechanical properties of glass’.

This definition captures microfluidics, since this technology augments the mechanical properties of glass by redirecting fluids within micro-channels.

Microfluidics fuses chemistry, physics, biology, fluid dynamics and microelectronics, which is responsible for processing the data collected by on-chip sensors.

We can envisage using artificial intelligence to learn from this data and expedite advances in medical and pharmaceutical development.

Microfluidics and Switchable Glass

When combining microfluidics with optically-switchable glass, we envisage an arrangement as shown below. 

This stack can influence the radiation which is exposed to chemical / biological reactions taking place inside the chip.

One possible implementation could use dyed liquid crystals (DLC) smart glass, stacked on top of a microfluidics chip, allowing electrical control of light.

Dyed liquid crystal smart glass, stacked on top of a microfluidics chip to control light (dimensions are not to scale)

This arrangement could filter infrared, ultraviolet or visible light, allowing for fine grained control over the radiation incident on the chip, and aiding in the development of photosensitive drugs such as :-

• Acetaminophen
• Codeine
• Chloroquine
• Ethotoin
• Ketoprofen
• Simethicone
• Zolpidem

Placing microfluidics chips under optically-switchable glass layers, and under the direction of AI-enabled algorithms would enable multiple test scenarios, each with a different radiometric profile.

Furthermore, automating this process would give faster results and larger datasets with improved learning outcomes.

Outlook

We believe that the Microfluidics industry is comparable to the Microelectronics industry, with far-reaching impacts on many vertical sectors.

We consider Microfluidics to be a type of smart glass, since it can augment the mechanical properties of ‘specialty glazing’, a market segment valued at USD 2.9 Billion in 2024.

Combined with optically-switchable (smart) glass, microfluidics could provide faster, cheaper lab analyses for the development of photosensitive pharmaceuticals and cosmetics. 

The data produced could feed into AI tools for advanced data analysis for enhanced drug development.

We will be covering more aspects of this technology in future, so follow us on our Linkedin public group to learn more.