The appeal of touchscreen devices are global not just because it is cool to use, but because it can actually make lives easier. Now, the touchscreen experience may be up another notch as researchers have developed a 3D nanowall technology that can revolutionize the entire smartphone industry.
All touchscreen devices from tablets to vendo machines use transparent electrodes. The device surface is coated with an almost invisible pattern of conductive material to perform its function. Through this, the device is able to determine where exactly the user puts a finger on the screen.
The two main properties that screen coating require are superb transparency and high-level of conduction.
At present, smartphones use indium tin oxide as coating because it is fairly transparent and has been sufficiently researched. However, indium tin oxide only possesses moderate conductive abilities.
Researchers from the ETH University in Zurich, Switzerland, headed by Dimos Poulikakos, were able to use 3D print technology to develop a new kind of transparent electrode or "nanowall" that is so thin, it is very hardly detectable via the naked eye.
Best Of Both Worlds
The newly developed electrodes are said to boast both high levels of transparency and conductive capacities. With this, one can expect the devices that use this technology can enjoy better screen quality and quick and precise responsiveness with every touch.
For the main materials, the researchers decided to use gold and silver as these are said to conduct electricity better. There was only one problem: gold and silver are metals.
"While metal films possess the highest conductivity at room temperature, a decent optical transmittance can only be achieved with ultrathin films," the researchers wrote.
Because the metals are not transparent, the researchers had to utilize the third dimension.
"If you want to achieve both high conductivity and transparency in wires made from these metals, you have a conflict of objectives," said Poulikakos. He further explained that as the height of the cross-sectional area of the gold and silver wire increases, the grid's transparency plummets.
The solution? Make a metal wall that is only 80 to 500 nanometers thick, which are invisible when viewed from above. With the said measurement, the walls become two to four times taller than wider thus, boosting conductivity to an adequate high.
3D Printing
This is the first time that experts use 3D printing in creating the technology. For this project, they particularly turned to Nanodrip to generate the tiny metal electrodes.
Nanodrip was created by Poulikakos and colleagues in 2013 and involves using inks made from metals in a solvent. Through this process, a 3D structure may be created drop by drop when an electrical field draws tiny droplets of the metal ink out of a glass chamber.
The next challenge for the researchers is to amp up the method and create a print process so that it can be used in the industrial setting.
Other Applications
The team of experts believes that their technology will pose more advantages to touchscreen devices than existing techniques. For one, 3D nanowall technology is more cost-effective as it does not require a cleanroom environment. The new electrodes are also said to be more appropriate for large touchscreen devices because it's more conductive.
Other applications of the technology according to the researchers include solar cell enhancement for a more efficient electricity source and development of curved display via OLED technology.
The paper was published in the journal Advanced Materials.
Photo: Quinn Dombrowski | Flickr
