Researchers have developed a new way to design transparent conductors using metal nanowires that could enable less expensive and flexible touchscreens.
The research was conducted by the researchers at the University of Pennsylvania in collaborated with Duke University.
The current industry-standard material for making transparent conductors is indium tin oxide, or ITO, which is deposited as two thin layers on either side of a separator film. Contact, in the form of a fingertip or a stylus, changes the electrical resistance between the two ITO layers enough so that the device can register where the user is touching.
Professor Karen Winey said that there are two problems with ITO; indium is relatively rare, so its cost and availability are erratic, and, more importantly for flexible devices, it's brittle.
Meanwhile, metal nanowires are increasingly inexpensive to make and deposit; they are suspended in a liquid and can easily be painted or sprayed onto a flexible or rigid substrate, rather than grown in vacuum as is the case for ITO.
The Penn team's simulation provides further evidence for each variable's role in the overall network's performance, helping the researchers home in on the right balance of traits for specific applications. Increasing the coverage area of nanowires, for example, always decreases the overall electrical resistance, but it also decreases optical transparency; as more and more nanowires are piled on the networks appear gray, rather than transparent.
The study was published in the journal ACS Nano.