WHAT IS THE HISTORY OF MICROFLUIDICS?
Microfluidics is both the science which studies the behaviour of fluids through micro-channels, and the technology of systems that process or manipulate small (10-6 to 10-12 litres) amounts of fluids using microminiaturized devices containing chambers and channels through which fluids flow or are confined.
Applications and benefits of microfluidics
The first applications of microfluidic technologies have been in the areas of biological and chemical analysis, for which they offer a number of useful capabilities.
1. Capabilities of microfluidics
– To use very small quantities of samples and reagents
– To carry out separations and detection with high resolution and sensitivity
– To decrease the costs
– To shorten times for analysis
– To allow for devices with a small footprint
2. Microfluidics, an attractive technology for several fields
Microfluidics exploits the small size of channels and laminar flow of fluids inside them, due to the low Reynolds number. Microfluidics offers fundamentally new capabilities in control of concentrations of molecules in space and time.
These basic properties give rise to advantages that have made microfluidic technology attractive for biology, diagnostics and chemical synthesis in both industry and academia.
What is the history of microfluidics?
The history of microfluidics dates back to the 1950s, principally in inkjet printer manufacturing.
1. Origins of microfluidics, a fluid handling system for printers
The mechanism behind these printers is based on microfluidics; it involves the use of very small tubes carrying the ink for printing.
In the 1970s a miniaturized gas chromatograph was realized on a silicon wafer. By the end of the 1980s the first microvalves and micropumps based on silicon micro-machining had also been presented. In the following years several silicon based analysis systems have been presented. All these examples represent microfluidic systems since they enable the precise control of the decreasing fluid volumes on one hand and the miniaturization of the size of a fluid handling system on the other.
2. The expansion of microfluidics and developing microfluidic components
Over time, researchers spent a lot of time in developing new microfluidic components for fluid transport, fluid metering, fluid mixing, valving, or concentration and separation of molecules within miniaturized quantities of fluids.
As an example, in 2006, Fluigent was the first company to introduce a new disruptive way of handling fluids in microfluidics: microfluidics pressure pumps.
The use of a pressure based pump allows very responsive time and pulseless flow. At first it could only control the pressure of liquids in the microfluidic chips, but later on, by adding a flow sensor and a unique feedback control loop, Fluigent enabled the control of both pressure and flow rate. The precise control of fluids in a microfluidic device enables new sophisticated applications, which were not possible before.
Another important contribution has been the development of soft lithography in PDMS as a method for fabricating prototype devices and testing new ideas.
The key concept related to microfluidics is to integrate in a simple micro-sized system operations that commonly need a whole laboratory.
Currently, in microfluidic systems a traditional scale-up is substituted by multiplexing, thanks to the compact size of the device which dramatically shortens the time that it takes from formulation to production. This leads to the adoption of microfluidic technologies not only for analytical purposes but also for large scale manufacturing in process industries, particularly fine chemistry, food, environmental and pharmaceuticals. In more recent years microfluidic devices have also been extensively adopted as analytical tools for biochemistry and molecular biology applications.
Microfluidic systems also offer an excellent data quality and improved parameter control which allows for process automation while preserving the performance. They have the capacity to both process and analyze samples with minor sample handling. The association of the microfluidic chip and the fluid handling system is elaborated so that the incorporated automation allows the user to generate multi-step reactions requiring a low level of expertise and a lot of functionalities.
Recently, an increasing number of microfluidic-based devices, developed both in small start-ups and large pharmaceutical and biomedical companies, have been released and are entering the market.
The use of microfluidics, a technology whose development has just begun
Microfluidics offers revolutionary new capabilities. It is still quite a new technology and there is a lot of work to perform so that it will solve problems for users who are not experts in fluid physics such as clinicians, cell biologists, and public health officials.
In the near future there are going to be more microfluidic applications, making possible more precise analysis of various molecules, like DNA, proteins, bacteria, or analysis at the scale of a single cell. The continuing development of high-throughput screening and the Organ on a chip technology (enabling to help predicting the behaviour of potential new drugs in humans from performance in cells) will lead to faster and better drug development. With development of lab-on-a-chip and microTAS, new diagnostic products will be cheaper and faster, bringing benefits to developing countries.
The development of microfluidics has just begun!