Researchers have discovered ways to print 3D structures made from liquids. Scientists from the Department of Energy’s Lawrence Berkeley National Laboratory who made the discovery say this is the first step in creating liquid electronics that can mold to any shape for use in stretchable devices.
The discovery has been detailed in the journal Advanced Materials. To achieve the incredible task, scientists used a standard off-the-shelf 3D printer that they modified by adding a syringe that would add tiny amounts of water into a small box of silicone oil.
The water that was injected was seeded with gold nanoparticles while dispersed polymer ligands were added to the oil. Ligands are a group of atoms that bind to a metal atom.
When the gold-flecked water and the polymer tainted oil combined, the ligands pulled and bound with the gold nanoparticles. The result was a nanoparticle cloak around the water that stopped the water from breaking into drops.
Supersoap holds water together
The cloak maintains the water into a tube shape that allows it to be printed by the 3D printer. The researchers called the concoction a nanoparticle supersoap.
Like soap, this mix is a “surfactant,” or a substance that reduces the surface tensions of the liquids it comes in contact with. Motherboard gave a good example of how to imagine this: as we know oil and water don’t mix, but when dish soap is added to the mix it reduces their surface tension and allows them to mix, and for you to wash up greasy dishes.
However, unlike dish soap, oil and water when the ligands present in the oil and the gold nanoparticles from the water meet the result is vitrification. The same process that occurs when molten glass cools to its solid form.
Endless possibilities for liquid 3D printing
By capturing these processes inside the printer, the scientists were able to control the shape of the outcome. “This stability means we can stretch water into a tube, and it remains a tube.
Or we can shape water into an ellipsoid, and it remains an ellipsoid,” said Russell. “We’ve used these nanoparticle supersoaps to print tubes of water that last for several months.”
The results are the first step into the development of an entirely new kind of electronics. The 3D printed liquids could make possible flexible and stretchy devices.
Research opens doors to stretchy electronics
“It’s a new class of material that can reconfigure itself, and it has the potential to be customized into liquid reaction vessels for many uses, from chemical synthesis to ion transport to catalysis,” said Tom Russell, a visiting faculty scientist in Berkeley Lab’s Materials Sciences Division.
“We can squeeze liquid from a needle, and place threads of water anywhere we want in three dimensions.”
Russell developed the method and material in collaboration with Joe Forth, a postdoctoral researcher in the Materials Sciences Division, as well as other scientists from Berkeley Lab and several other institutions.
“We can squeeze liquid from a needle, and place threads of water anywhere we want in three dimensions,” said Forth. “We can also ping the material with an external force, which momentarily breaks the supersoap’s stability and changes the shape of the water threads. The structures are endlessly reconfigurable.”
Via: Berkeley Lab