Screen overlay for mobile phones

Chinese scientists are developing a transparent material that can be used to cover the surface of touch screens. This material emits electricity whenever someone touches the screen.

According to Live Science, researchers at the University of Lanzhou in China say that mechanical energy from the touch screen operation of electronic devices can be converted to electricity to charge the phone. , greatly extends the working time of the handset.

They have developed a new material, based on a transparent silicone rubber called PDMS . Lead wires made of lead zirconate titanate have a width of only about 700 nanometers, about 140 times the width of human hair, embedded in rubber.

Touch the touch screen to charge. Photo: TZIDO SUN.

As the rubber solidifies, the researchers use the electric field to align the rubber nanowires in line with the columns. This sorting process will set the electrical and visual properties for the coating. Every time there is a mechanical action on the rubber, such as touching the screen, the wires are bent, the current being generated by the piezoelectric phenomenon. Because the nanowires are aligned, they will react to multiple touches at the same time, generating as much energy as possible.

Because the strands are very small, the entire cover is almost transparent. Thus, the nanowires "can harness the power on a monitor without compromising its normal operation," said study author Yong Qin.

In addition, when the screen is covered, if viewed from a different angle from the device owner's perspective (looking straight at the screen), the nanowire diffracts light, can not see clearly, protects the privacy of the equipment owner.

In current experiments, touching the coating produces a 0.8 nanoampe current, about one millionth of the electrical current used in hearing aids. The next study will help to generate larger currents, boosting the efficiency of charging for mobile devices. Electromagnetic signals from the nanowires also help to develop touch screens with higher sensitivity, according to Qin.

The study was published online in Small on Jan. 13.