MICROFLUIDIC devices that are effective at a scale less than 100µm have been 3D-printed for the first time, which researchers say could revolutionise ‘lab on a chip’ fabrication.
Tiny ‘lab on a chip’ microfluidic devices allow the miniaturisation of biochemical operations normally handled in a laboratory. Precise analyses such as DNA sequencing and biochemical detection can be undertaken rapidly, in parallel and with fewer reagents, reducing cost and speeding up information-gathering. However, the devices are expensive and difficult to make, due to their intricate geometry.
A group at Brigham Young University in the US has now published a paper in Lab on a Chip detailing the first successfully 3D-printed truly microfluidic device. In doing so, they overcame issues of resolution that have prevented previous attempts from being effective at a scale less than 100µm.
Researcher Gregory Nordin said: “Others have 3D-printed fluidic channels, but they haven’t been able to make them small enough for microfluidics, so we decided to make our own 3D printer and research a resin that could do it.”
Their bespoke system used a form of additive 3D printing called digital light processing stereolithography, whereby a light source is used to turn liquid resin into a solid object, one layer at a time. The group found that by using an LED with a wavelength of 385 nm, as opposed to the more common 405 nm, it was able to dramatically increase the available selection of UV absorbers for resin formulation.
By screening potential candidates, the final resin formulation was capable of achieving flow channel cross sections as small as 18 μm by 20 μm. The authors said that aside from improving the size of features possible in 3D-printed microfluidics by a factor of 100, their approach cuts down on time and hassle, being able to create a device in 30 minutes without the use of clean rooms.
Co-author Adam Woolley said: “It’s not just a little step; it’s a huge leap from one size regime to a previously inaccessible size regime for 3D printing. It opens up a lot of doors for making microfluidics more easily and inexpensively.”
“We’re deliberately trying to start a revolution in how microfluidic devices are fabricated,” Nordin added.
Lab on a Chip: http://doi.org/cbtf
