Low-cost microfluidics can be a sticky problem

May 12, 2006

A deceptively simple approach to bonding thermoplastic microchannel plates together with solvent could be used for low-cost, high-volume production of disposable "lab-on-a-chip" devices, according to researchers from the National Institute of Standards and Technology (NIST) and George Mason University (GMU).

Microfluidics is considered a highly promising technology for performing rapid and inexpensive chemical and biochemical analyses. The defining feature of microfluidics is the use of tiny channels less than a fraction of a millimeter wide to move samples and reagents through the device. For high-volume production, the channels likely will be molded or embossed in high-quality thermoplastic and then sealed with a cover plate. Bonding the two pieces together securely without blocking or altering the tiny channels is a key manufacturing issue.

One approach is to weld the two plates together by clamping them and heating the plastic to the point where the polymer chains begin to diffuse together. This requires just the right combination of time, pressure and temperature--which unfortunately has to be fine-tuned for each new lot of plastic. The other method is to weld the pieces with a solvent-type glue, like a model plane, but as model-builders will appreciate, the problem is keeping the glue where you want it and away from where you don't want it.

In a recent paper in Analytical Chemistry, a team from NIST and GMU suggest that the answer is simple: use the channels. They clamp the two plates together, inject a tiny amount of solvent at one end of the network of channels and apply vacuum at the other end. As the solvent is sucked through the channels, too fast to clog them, a minute amount is drawn between the plates by capillary action and welds them together. Total welding and incubating time: about 8 minutes. To demonstrate utility, the team successfully performed high-efficiency electrophoretic separation of 400-base single-strand DNA ladders, a typical microfluidics application, in the devices fabricated using the technique.

Citation: J.J. Shah, et. al., Capillarity induced solvent-actuated bonding of polymeric microfluidic devices, Analytical Chemistry 2006; 78(10) pp 3348 - 3353.

Source: NIST

Explore further: 3D printing technique explored to help treat type 1 diabetes

Related Stories

Galapagos volcano calms, pink iguanas out of danger

19 minutes ago

A volcano in the Galapagos Islands whose fiery eruption raised fears for the world's only population of pink iguanas has calmed, sparing the unique critters from danger, officials said Tuesday.

On-demand X-rays at synchrotron light sources

33 minutes ago

Consumers are now in the era of "on-demand" entertainment, in which they have access to the books, music and movies they want thanks to the internet. Likewise, scientists who use synchrotron light sources ...

New chip makes testing for antibiotic-resistant bacteria faster, easier

39 minutes ago

We live in fear of 'superbugs': infectious bacteria that don't respond to treatment by antibiotics, and can turn a routine hospital stay into a nightmare. A 2015 Health Canada report estimates that superbugs have already cost Canadians $1 billion, and are a "serious and growing issue." Each year two million people in the U.S. contract antibiotic-re ...

Recommended for you

Why Americans can't buy some of the best sunscreens

9 hours ago

With summer nearly here, U.S. consumers might think they have an abundance of sunscreen products to choose from. But across the Atlantic, Europeans will be slathering on formulations that manufacturers say provide better ...

Expanding the code of life with new 'letters'

9 hours ago

The DNA encoding all life on Earth is made of four building blocks called nucleotides, commonly known as "letters," that line up in pairs and twist into a double helix. Now, two groups of scientists are reporting ...

'Cold soak' process turns up the heat on wines

10 hours ago

Those pondering which elements make the best drop of wine may be surprised to learn different climates produce mixed results when it comes to wines made using the 'cold soak' process.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.