Tiny developments make a big splash in life science and materials applications.
Interest in microfluidics technology began as far back at 1975, when researchers at Stanford Univ. developed a miniature gas
chromatograph fabricated on a silicon wafer.
The technology advanced rapidly during the
1990s, when the first commercial lab-on-a-chip system was launched.
Since microfluidics origin, chemists and
engineers have used microelectronics and
analytical biochemistry concepts to generate
microfluidic chips with networks of channels
through which fluids move, allowing a range
of analytical, synthetic and other fluidic tasks
to be performed. In microfluidics, there
are two main branches: lab-on-a-chip and
benchtop analytical instrumentation. Lab-on-a-chip devices are small, low-power devices
that integrate functions like dispensing,
mixing, separation and detection, and are used
in medical diagnostics and other applications.
Benchtop analytical instruments are larger,
high-power devices that use microfluidic
technology to boost the speed of analysis.
Microfluidics in the life
The pharmaceutical industry uses
microfluidics to overcome issues with
poor aqueous encapsulation rates and size
heterogeneity during bioencapsulation.
“Thousands of droplets can be generated per
second with high particle size homogeneity
and increased encapsulation efficiency, and
single cells can be encapsulated,” says Mike
Hawes, Chief Commercial Officer, Dolomite
Microfluidics. Typically applications are cell
sorting, protein analysis, high-throughput
assays and next-generation sequencing.
In health care, microfluidics is influencing
developments in molecular biology, drug
delivery and discovery, diagnostics, forensics,
analytical methods and nucleic acid analysis.
PCR reactions can be performed up to
10 times faster with current microfluidic
technology, and thermocyclers can amplify
DNA contained in less than 5 µL of solution,
enabling parallel processing of multiple
trace samples. Microfluidics is also used for
drug development studies of multicellular
And, over the past few years, several
companies have been working to
commercialize microfluidic technologies
for automated multiple sample analyses.
Fluidigm has integrated pneumatic
rubber valves in microfluidic circuits to
commercialize digital PCR and single-cell
manipulations. RainDance Technologies Inc.
has developed a single-molecule picodroplet
system for digital PCR. These picodroplets
are compatible with PCR machines and
next-generation sequencers. And, recently,
Advanced Liquid Logic Inc., now Illumina,
has developed electro-wetting technology
that manipulates discrete droplets in a
microfluidic device without pumps, valves
or channels. Illumina has also released its
Neoprep microfluidics system to automate
sample preparation for its next-generation
Microfluidics in the materials
In particle manufacture, microfluidic
methods are used to create nanostructured
materials. This can lead to the development
of “smart” materials, such as those for self-healing or sustained release, novel tissue
scaffolds, composites and nanocomposites,
ultrasound contrast agents and quantum dots.
“Another class of small-volume materials
science is based on handling dangerous,
toxic and explosive reagents,” says Hawes.
“Supercritical microfluidics combines the
advantage of size reduction with the unique
properties of supercritical fluids, opening new
chemical possibilities, supercritical water and
carbon dioxide.” It also enables synthesis of
high-quality nanocrystals; controlled, low-temperature reactions between explosive
reactants; and investigation of exothermic
reactions and novel chemistry applications.
Microfluidics in materials science is also
offering fabrication of polymeric particles
that can be used in a variety of applications,
such as systems for controlled chemical
release, optical materials, media and various
biological applications. “Microfluidic
chips can provide physical and chemical
properties of polymeric particles, such as
their shape, size, porosity, surface charge
and hydrophilicity or hydrophobicity, that
influence the particle function,” says Krystyna
Hohenauer, Portfolio Director, Automation
and Microfluidics, PerkinElmer.
A game-changer for science
Microfluidic technology shrinks the scale
down to nanoliter and picoliter volumes
of biological samples. These devices can
be fabricated from various types of glass,
polymers and silicon, and can operate at
picoliter sample sizes, yielding faster reactions
“Integration of automation with
microfluidics allows multiple sample analyses
with reduced manual labor and time,” says
Hohenauer. “Hence, microfluidics offers
new tools in material science genomics,
proteomics, drug discovery, high-content
imaging and next-generation sequencing
From a life science perspective,
microfluidic technology offers rapid analysis
times, integration of multiple processing steps
and uses very small sample and volumes,
decreasing costs and enabling small quantities
of precious samples to be stretched further.
“The quantities of waste products are also