New liquid 'lab on a chip' automates chemical reactions
A team at the Department of Energy’s Lawrence Berkeley National Laboratory is interested in applying 3D printing technology to liquids.
Last year, one of Berkeley Lab’s staff scientists teamed up with a visiting scholar, and the two of them developed an innovative approach that allowed forming various kinds of liquid shapes — such as droplets or rotating threads — inside of other liquids.
The researchers’ published paper on their findings indicated that they constructed shapes out of water within oil. That feat stimulated the research team to think about the possibility of printing liquids inside of defined channels and making liquid flow through them without causing damage to the structures.
They eventually realized that succeeding in that goal would open a world of possibilities that could positively affect numerous industries — the pharmaceutical sector among them. That revelation resulted in the design and printing of the functional fluidic device that came about with help from last year’s conclusions.
More streamlined drug screening
While writing their research paper, the scientists also discussed how the system could eventually demonstrate autonomous learning, such as by detecting the properties of applicable channels. If pharmaceutical researchers apply this fluidic device to screening drug candidates — such as by seeing how a medicine reacts within the device when exposed to chemicals — the timeframe could become even more streamlined.
“New fluidics technologies, such as ours, allow you to carry out cell-based assays in small volumes,” Brett Helms, one of the researchers and a staff scientist at Lawrence Berkeley National Laboratory, told us. “In this way, they can serve as a platform for screens where only limited material may be available, e.g., from patient biopsies.”
“The method, if used with cells, may carry advantages in that the entire all-liquid device is ‘soft,’ and therefore less perturbative to sensitive biological samples,” he said.
How does the fluidic device work?
One of the researchers working on the study made a glass substrate with a specific pattern on it. Then, one liquid containing nanoscale clay particles and another that had polymer particles in it was printed onto the substrate. Next, within only milliseconds, the two liquids came together and create a tiny channel about a millimeter in diameter.
Following the formation of such channels, users can insert catalysts. Next, they build liquid bridges so fluids flowing through the newly-created channel encounter the catalysts in a certain order, triggering chemical reactions to make desired compounds. Controlling these processes with a computer allows users to automate particular tasks, such as catalyst placements or the reaction sequences necessary to create molecules.
The researchers also mentioned that they could program the 3D-printed device to work like an artificial circulatory system. In that case, it would separate molecules flowing through the channel and get rid of unwanted byproducts while it simultaneously went through the steps of chemical synthesis.
What's Next?
The team working on this project noted that they are pleased to have combined flow chemistry and fluidics in a way that's easy to program and is otherwise user-friendly. They say the next thing on their agenda is to electrify the walls of the fluidic device's channel using conductive nanoparticles. Doing so would allow them to diversify the kind of chemical reactions that could be explored.
Although this fluidic device isn't solely intended for screening drug candidates, the technology could make that all-important step substantially more straightforward and efficient.
