Microfluidics is a technology in its infancy, and its potential for manufacturing very small products will certainly attract investment and spark advances. But will it change manufacturing industries in a way similar to the transition from electronics to microelectronics? Fluidic self-assembly itself may lead to smaller and less expensive RFID tags.

We’re all aware of the importance of keeping track of raws, processing and pre-shipping inventory. Some manufacturers have incorporated RFID, active or passive, but all have wished we could increase the promise of business survival.

Fluidic self-assembly may eliminate robotic assembly and permit precision manufacturing of much smaller RFID tags, according to R&D Magazine. Even more, Purdue University’s Steven Werely and Hyphenated Systems’ Edward Robinson and Terence Lundy say that random fluidic transport allows the placement of very large numbers of devices in minutes. “Particles suspended in fluid will automatically self-assemble into mating cavities in the substrate.”

In their comprehensive article, Werely, Robinson and Lundy claim microfluidics is a technology only in its infancy and its potential for manufacturing very small products will certainly attract investment and spark advances. Perhaps microfluidics will change many manufacturing industries in a way similar to the transition from electronics to microelectronics. Fluidic self-assembly itself may some day lead to smaller and less expensive RFID tags.

“Because the field of microfluidics is a relatively immature field, numerical simulations of microfluidic systems can be extremely valuable both in terms of providing a research tool and as an efficient design and optimization tool,” according to professor and vice chair of the University of Washington Dept. of Bioengineering Paul Yager. “By incorporating the complexities of channel geometry, fluid flow rates, diffusion coefficients and possible chemical interactions into a numerical model, the behavior of a particular system can be accurately predicted when an intuitive prediction may be extremely difficult,” writes Eric Shilling, the main contributor to an article at Yager’s site.

“For example, a custom coded numerical model has been used to predict differences in the diffusive scaling laws across the depth of a microchannel. Numerical modeling also allows visualization of complex flow phenomena that may not be easily obtained experimentally.”

The areas in which microfluidics will most likely play a role include “new methods to analyze and control biochemical systems, according to Stanford University’s Microfluidics Laboratory. The technology has the potential to achieve the following:

• Exploration of single-cell and single-molecule biophysics;
• Miniaturization and portability of chemical assays;
• Cost savings of minimal reagent use; and
• Potential for massively-parallel and high-throughput biochemical analyses.

Engineering challenges include the realization of optimized processes in mixing, reaction, separation, pre-concentration and detection of chemical species. As such, a number of highly regarded academics are focusing their attention on improving the science and application of microfluidics.

For example, the Stanford Microfluidics Laboratory exploits the physical regimes associated with micro- and nano-scale devices in order to achieve new functionality. The long-term goal is to enable chemical and biological discoveries, help define the role of engineers in microfluidics, and educate the future leaders in the field.”

At Brown University, the microfluidics emphasis is closer to zoology and microbiology. There, research interests cover a wide variety of topics in fluid mechanics, including the following:

• Micro- and nanometer scale fluid mechanics;
• Animal flight mechanics (particularly bat flight);
• Flows associated with bacterial motility;
• Turbulent flows, turbulent drag reduction and turbulent flow control; and
• Experimental and diagnostic techniques for fluid mechanics.

The researchers at Duke University approach microfluidics from a more theoretical view and physical perspective. “Research in Dr. Richard Fair’s laboratory there has focused on the use of electrowetting arrays to demonstrate the digital microfluidic concept. Electrowetting is essentially the phenomenon whereby an electric field can modify the wetting behavior of a droplet in contact with an insulated electrode. If an electric field is applied non-uniformly then a surface energy gradient is created which can be used to manipulate a droplet sandwiched between two plates. Electrowetting arrays allow large numbers of droplets to be independently manipulated under direct electrical control without the use of pumps, valves or even fixed channels.”

Finally, the University of California – Santa Barbara (UCSB)’s Microfluidics laboratory conducts research in two primary areas: the investigation of fluid mechanics at the microscale, and its application to optimize microelectromechanical systems (MEMS)-based biosensors. In the microfluidics area, researchers study fluid flow in devices with length scales of order one to one hundred microns. Interests at UCSB include the development of micron resolution particle image velocimetry (micro-PIV), micro-mixing devices and protocols, particle manipulation using dielectrophoresis (DEP) and AC electrokinetics, and the analysis of boundary conditions at the microscale.”