The lab-on-a-chip uses a specially patterned glass substrate. When two liquids - one containing nanoscale clay particles, another containing polymer particles - are printed onto the substrate, they come together at the interface of the two liquids and within milliseconds form a very thin channel or tube about 1 millimeter in diameter.
Once the channels are formed, catalysts can be placed in different channels of the device. The user can then 3D-print bridges between channels, connecting them so that a chemical flowing through them encounters catalysts in a specific order, setting off a cascade of chemical reactions to make specific chemical compounds. And when controlled by a computer, this complex process can be automated to execute tasks associated with catalyst placement, build liquid bridges within the device, and run reaction sequences needed to make molecules.
"What we demonstrated is remarkable. Our 3D-printed device can be programmed to carry out multistep, complex chemical reactions on demand," said Brett Helms, a staff scientist in Berkeley Lab's Materials Sciences Division and Molecular Foundry. "What's even more amazing is that this versatile platform can be reconfigured to efficiently and precisely combine molecules to form very specific products, such as organic battery materials."
Last year the lab developed a new technique for printing various liquid structures - from droplets to swirling threads of liquid - within another liquid. "After that successful demonstration, a bunch of us got together to brainstorm on how we could use liquid printing to fabricate a functioning device," said Helms. "Then it occurred to us: If we can print liquids in defined channels and flow contents through them without destroying them, then we could make useful fluidic devices for a wide range of applications, from new types of miniaturized chemical laboratories to even batteries and electronic devices."
This was extended to the configurable, multitasking design that can be programmed to function like an artificial circulatory system that separates molecules flowing through