Scientists used acoustic waves to encourage the formation of smaller droplets from more viscous liquids. Photo by Daniele Foresti/Jennifer A. Lewis/Harvard University
Aug. 31 (UPI) -- Scientists have found a way to print with sound. The new technology will help printers exert more precise control over the shape and viscosity of ink droplets.
The acoustic printer won't be printing term papers or greeting cards. Instead, the technology could be used to synthesize biopharmaceuticals and cosmetics, as well as optical and conductive materials.
"By harnessing acoustic forces, we have created a new technology that enables myriad materials to be printed in a drop-on-demand manner," Jennifer Lewis, a profess or bioengineering at Harvard University, said in a news release.
Scientists have previously used sound waves to levitate particles and look for contaminants. Researchers have also bounced sound waves through a maze and reflected sound waves back toward their original source with unprecedented efficiency.
Now, scientists have used sound to advance printing technology.
Currently, microcapsules used for drug delivery are made using inkjet printers. The technology can only handle liquids ten times more viscous than water. The new printer can shape and deposit microcapsules made from much more viscous liquids, including biopolymer and cell-laden solutions.
"Our goal was to take viscosity out of the picture by developing a printing system that is independent from the material properties of the fluid," said Daniele Foresti, a material scientist at Harvard's Wyss Institute.
As mentioned, sound waves have previously been used to levitate liquid droplets. The latest technology deploys acoustic waves to enhance, rather than assist, gravity.
"The idea is to generate an acoustic field that literally detaches tiny droplets from the nozzle, much like picking apples from a tree," said Foresti.
The normal low and slow droplet formation process causes microcapsules to be too big and clunky. By pushing droplets out more efficiently, scientists can produce smaller, more delicately designed deposits.
In the lab, scientists successfully printed microcapsules using a variety of liquid solutions, including honey, stem cell inks, optical resins and liquid metals.
Researchers detailed their new technology this week in the journal Science Advances.
"Our technology should have an immediate impact on the pharmaceutical industry," said Lewis. "However, we believe that this will become an important platform for multiple industries."