Thanks to scientists in the US we’re now one step closer to being able to print flexible electronics onto anything at all.
It means that in the future we may be able to print electronic applications onto our clothes, personal possessions, or even to form soft robots.
Scientists from Purdue University, US, have show how humble inkjet-printing technology can be used to mass-produce electronic circuits made of liquid metal alloys.
“We want to create stretchable electronics that might be compatible with soft machines, such as robots that need to squeeze through small spaces, or wearable technologies that aren’t restrictive of motion,” said Rebecca Kramer from the university.
“Conductors made from liquid metal can stretch and deform without breaking.”
A printable ink is made by dispersing liquid metal in a non-metallic solvent, which breaks up the liquid metal into nanoparticles that can then be printed.
“This process now allows us to print flexible and stretchable conductors onto anything, including elastic materials and fabrics,” Kramer said.
The ability to easily print conductors onto any material has the potential to be utilised in the field of soft robotics. New manufacturing techniques will need to be developed before any method of printing the electronics can be applied commercially.
Wearable soft robotics is rapidly expanding area of robotics that will be able to enhance human capabilities through adapting to an individual’s needs.
In the UK, funding has been made available for one group of researchers to create wearable soft robotics that can aid the mobility and independence of those who are movement –impaired or disabled.
The researchers behind the UK-based research said soft robotics in wearable technology will become a “natural and unobtrusive part of our daily lives”.
Meanwhile, another soft robot that has already been created without electronic components that could help provide extra force for reaching and lifting.
The researchers of the latest work say that is crucial that liquid metal nanoparticles are created, as regular liquid metal is not able to be passed through a inkjet setup.
“What we do is create liquid metal nanoparticles that are small enough to pass through an inkjet nozzle,” Kramer said.
“Sonicating liquid metal in a carrier solvent, such as ethanol, both creates the nanoparticles and disperses them in the solvent.
“Then we can print the ink onto any substrate. The ethanol evaporates away so we are just left with liquid metal nanoparticles on a surface.”
After the nanoparticles have been printed they must be rejoined to make the material conductive.
Initially the nanoparticles are coated in a substance that prevents them being electronically conductive, but applying pressure to the printed nanoparticles removes this layer. This gives the choice of which areas are made electronically conductive.
The research is due to be published in the Advanced Materials journal on April 18.
Images courtesy of Purdue University