Up till now, metals were printed onto fabrics by coating them with plastic. The new approach, however, allows metal inks to cover entire fibres rather than simply coating the surface of the fabric.
In a media brief, the researchers explained that to coat the fibres, they first covered them in microscopic particles of silicon, and then submerged the material into a solution containing metal ions. The process, known as SIAM or Si ink-enabled autocatalytic metallization, allowed the metals to spread throughout the material as the ions were deposited on the silicon particles.
Since the metal coats the entire fabric, it allows it to maintain its ability to absorb water and it's flexibility.
To prove the technique, the team lead by bioengineer Firat Güder tried different things, among them the creation of silver coil antennas on paper, which can be used for data and power transmission in wireless devices such as Oyster cards and contactless payment systems. They also used the method to deposit silver onto paper and then added zinc onto the same paper to form a battery.
In other words, they say the technique could be used to ultimately incorporate batteries, wireless technologies and sensors into things such as paper and cotton textiles.
“The beauty of this approach is that it can also combine different technologies to serve a more complex application, for example low-cost sensors can be printed on paper that can then transmit the data they collect through contactless technology. This could be particularly useful in the developing world where diagnostic tests need to be conducted at the point of care, in remote locations and cheaply," said researcher Max Grell, who published the team's findings in an article published in the journal Advanced Functional Materials.