Currently, manufacturing of microfluidic devices is a time intensive process and involves the use of high precision manufacturing technologies. However, there are certain bottlenecks with each technology, and we shall explore more about them in this post.
Quick Recap: Microfluidic devices have found profound use in the Healthcare segment. Few of the applications of microfluidic devices includes - Point-of-care devices, Lab-on-a-chip devices, Organ-on-a-chip devices, among many others. (These applications pertain to Healthcare, and there are many more segments where microfluidics plays a pivotal role.)
Now, each application requires the use of different materials, designs, and micro-components, to achieve a given objective. This leads to utilizing different manufacturing technologies for the fabrication of microfluidic devices.
The manufacturing technologies utilized can be broadly classified into three categories: Subtractive manufacturing, Additive manufacturing (3D printing), and Forming.
In Subtractive manufacturing, the design is printed (or machined) on a material substrate by removing material either through physical contact by a tool, or high temperature evaporation, or chemical etching. This type is generally a Series Production process. In some cases, Batch Production is also possible.
The preferred subtractive manufacturing technologies include:
a. CNC micromachining
b. LASER ablation
c. Chemical Etching
d. Electric Discharge Machining - EDM (only for electrically conductive materials)
e. Electrochemical Machining - ECM (only for electrically conductive materials)
f. Electrochemical Discharge Machining - ECDM (also known as Spark Assisted Chemical Engraving - SACE)
In Additive manufacturing, the design is printed by depositing material layer-by-layer on a substrate. Additive manufacturing provides the flexibility of manufacturing complex 3D designs, such as bio-printing of human heart, liver and other organs.
The common Additive Manufacturing Technologies include:
a. 3D printing
b. Chemical Vapour Deposition
c. Physical Vapour Deposition, and others
Forming technologies involve the utilisation of molds to manufacture microfluidic chips.
The common Forming technologies include:
a. Injection Molding
b. Hot Embossing
c. Lithography** based techniques - Photo-lithography, Soft-lithography, and others
Again, the manufacturing process depends on the requirement of the product developer/ researcher/ company. The application of microfluidic device is the major factor that influences the choosing of a manufacturing technology. Other factors that influence include:
a. Type of Material
d. Volume of manufacturing (Scale)
e. Surface property (depends on the application - high surface smoothness for flow based microfluidics)
g. Environment of device operation
h. Ease of Transportation, and others
However, we have observed common bottlenecks in all these technologies -
a. the high cost of fabrication,
b. inflexibility to manufacture complex designs, and
c. absence of material agnostic fabrication technologies.
Also, the manufacturing technologies utilized during the initial stages (proof-of-principle, proof-of-concept, and prototyping stages) of microfluidic device development, is far more different from technologies used for large volume production. Hence, there is a wide-gap in translating microfluidics from laboratory to the market.
This is a problem that MeuKron is solving for its customers.
We shall delve into the merits and demerits of each type of manufacturing technology in the coming series of blogs.
Until then, take care. Ciao!
** Although lithography techniques are a form of subtractive or additive manufacturing, they are predominantly used for the fabrication of molds (and not directly the microfluidic chips). Hence we have categorized it as a Forming technology.