Silver Nanowires Could Be the Key to Flexible Touchscreens

Traditional touchscreen material is not ideal for a future filled with flexible devices. Currently, touchscreen devices like smartphones and tablets rely on electrodes made from indium tin oxide (ITO), a material that is expensive to source and process, as well as very brittle.

A team of researchers from the University of Surrey, in collaboration with M-SOLV Ltd., a touch-sensor manufacturer, has discovered that silver nanowires are an ideal material for flexible touchscreen technologies.

The material can also be manipulated and tweaked for performance in other applications.

In recent years, researchers have explored ITO alternative materials such as graphene, carbon nanotubes and random metal nanowire films.

This study, however, showed how silver nanowire films are shaping up to be the strongest competitor, due to transmittances and conductivities, which can match and exceed those of ITO. Silver nanowires consist of wires that are over a thousand times thinner than a human hair and form an interconnected conductive network.

Silver nanowires are an ideal material for current and future flexible touchscreen technologies. (Image credit: Getty Images via University of Surrey)

“Our research hasn’t just identified silver nanowires as a viable replacement touchscreen material, but has gone one step further in showing how a process called ‘ultrasonication’ can allow us to tailor performance capabilities,” said Matthew Large, first author on the research. “By applying high-frequency sound energy to the material we can manipulate how long the nanosized ‘rods’ of silver are. This allows us to tune how transparent or how conductive our films are, which is vital for optimizing these materials for future technologies like flexible solar cells and roll-able electronic displays.”

In the course of their study, the team produced a fully operating five-inch multi-touch sensor like the ones typically used in smartphone technology. They found it performed comparably to one based on ITO but used significantly less energy to produce.

So, in addition to performing well, silver nanowires can be produced in a less energy-intensive manner, proving to be a green alternative, too.

“The fact that the nanowire films are processed by the same laser techniques as ITO makes the transition from ITO to nanowires really straightforward. It won’t be long before we are all using nanowires in our electronic devices,” said Maria Cann, a technologist from M-SOLV.

The team is looking to develop the process further to make it more practical for industrial purposes.

One challenge the team will have to face is the current cost of silver nanowires. The team is collaborating with M-SOLV and a graphene supplier, Thomas Swan, to use a nanowire and graphene combination in the electrodes to reduce the cost.