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: Researchers bring clean energy a step closer

add to favorites email to friend print save as pdf

Related Stories

Living in the genetic comfort zone

4 hours ago

The information encoded in the DNA of an organism is not sufficient to determine the expression pattern of genes. This fact has been known even before the discovery of epigenetics, which refers to external ...

'Bright spot' on Ceres has dimmer companion

6 hours ago

Dwarf planet Ceres continues to puzzle scientists as NASA's Dawn spacecraft gets closer to being captured into orbit around the object. The latest images from Dawn, taken nearly 29,000 miles (46,000 kilometers) ...

Key facts on US 'open Internet' regulation

6 hours ago

A landmark ruling by the US Federal Communications Commission seeks to enshrine the notion of an "open Internet," or "net neutrality." Here are key points:

Spotify deals with random shuffle and we mortals

6 hours ago

How do we mortals perceive random sequences? An entry in the question-and-answer site Quora focused on a question involving a music-streaming service Spotify. That question signifies how we perceive what ...

Recommended for you

Researchers bring clean energy a step closer

Feb 27, 2015

For nearly half a century, scientists have been trying to replace precious metal catalysts in fuel cells. Now, for the first time, researchers at Case Western Reserve University have shown that an inexpensive metal-free catalyst ...

The construction of ordered nanostructures from benzene

Feb 27, 2015

A way to link benzene rings together in a highly ordered three-dimensional helical structure using a straightforward polymerization procedure has been discovered by researchers from RIKEN Center for Sustainable ...

Superatomic nickel core and unusual molecular reactivity

Feb 27, 2015

A superatom is a combination of two or more atoms that form a stable structural fragment and possess unique physical and chemical properties. Systems, that contain superatoms, open a number of amazing possibilities ...

Oat breakfast cereals may contain a common mold-related toxin

Feb 25, 2015

Oats are often touted for boosting heart health, but scientists warn that the grain and its products might need closer monitoring for potential mold contamination. They report in ACS' Journal of Agricultural and Food Chemistry that s ...

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.