September 22, 2014
LEGO-Inspired Components Could Make Microfluidic System Development Cheaper, Easier
Chuck Bednar for redOrbit.com - Your Universe Online
Drawing inspiration from LEGO® building blocks, researchers have developed a new type of component that makes it possible to construct a 3D microfluidic system by simply snapping together small modules by hand.According to the USC Viterbi School of Engineering team behind the breakthrough, these so-called “labs on a chip” are used by experts working in biotechnology, chemistry and other scientific fields to precisely manipulate small volumes of fluids for use in DNA analysis, pathogen detection, clinical diagnostic testing and synthetic chemistry.
These systems are typically built in a cleanroom on a two-dimensional surface using the same technology developed to produce integrated circuits for the electronics industry, they explained. This can be an expensive and time-consuming process, as making a single device often requires researchers to design, assemble and test multiple different versions of a single device – a process that can take up to two weeks and cost thousands of dollars.
“You test your device and it never works the first time,” explained USC graduate student Krisna Bhargava. “If you’ve grown up to be an engineer or scientist, you've probably been influenced by LEGO® at some point in your childhood. I think every scientist has a secret fantasy that whatever they’re building will be as simple to assemble.”
Along with USC chemical engineering and materials science professor Noah Malmstadt and biomedical engineering graduate student Bryant Thompson, Bhargava, from the university’s Mork Family Department of Materials Science set out to find a way to make the construction process simpler, less expensive and less time-consuming.
The study authors, whose work appears in Monday’s edition of the Proceedings of the National Academy of Sciences (PNAS), started by identifying the basic elements typically used in microfluidic systems. However, after spending some time separating the functions of the devices into standardized modular components, similar to how electrical engineers break down circuitry, they decided to consider a new approach.
“The founders of the microfluidics field took the same approach as the semiconductor industry: to try to pack in as much integrated structure as possible into a single chip,” Bhargava explained. “In electronics, this is important because a high density of transistors has many direct and indirect benefits for computation and signal processing.”
“In microfluidics, our concerns are not with bits and symbolic representations, but rather with the way fluidics are routed, combined, mixed, and analyzed; there’s no need to stick with continuing to integrate more and more complex devices,” he added. So he and his colleagues decided to borrow an approach from the electronics industry.
Bhargava’s team came up with the idea of 3D modular components that encapsulated the common elements of microfluidic systems, as well as a connector capable of attaching those individual components together. They devised computer models for eight modular fluidic and instrumentation components (MFICs), each of which would perform a simple task and would be about one cubic centimeter in size, or slightly smaller than a traditional six-sided die.
The study authors said that their work in developing these MFICs marks the first time that a microfluidic device has been broken down into individual components that can be assembled, disassembled and re-assembled repeatedly. They attribute their success to recent breakthroughs in high-resolution, micron-scale 3D printing technology.
“We got the parts back from our contract manufacturer and on the first try they worked out better than I could have dreamed. We were able to build a working microfluidic system that day, as simple as clicking LEGO® blocks together,” said Bhargava, whose work was funded in part by the National Institutes of Health (NIH).
“You pull out everything you think is going to work, you stick it together and you test it,” he continued. “If it doesn’t work, you pull part of it out, swap out some pieces and within a day you’ve probably come to a final design, and then you can seal the system together and make it permanent. You have a massive productivity gain and a huge cost advantage.”
“MFICs will vastly increase the productivity of a single grad student, postdoc, or lab tech by enabling them to build their own instruments right in the lab and automate their workflow, saving time and money,” added Malmstadt. “People have done great things with microfluidics technology, but these modular components require a lot less expertise to design and build a system. A move toward standardization will mean more people will use it, and the more you increase the size of the community, the better the tools will become.”