Nano-scale piezoelectric light emitting LED array or can promote fingerprint scanning and tactile skin technology

What are the common points between electronic signatures, fingerprint scanning, and robotic tactile skin? Thanks to a new system that can convert zinc oxide nanowire arrays into miniature LEDs, these three technologies will soon be promoted. Each "line" responds to externally applied mechanical pressure in a shiny way. By analyzing tiny "dot mosaics," the computer can produce a high-resolution image of surface pressure. Since 2009, piezoelectric LED technology ("piezo-phototronic LED") has been developing.

The team was led by Professor Wang Zhonglin from the Georgia Institute of Technology.

The nanowires come from a layer of gallium nitride film, and the light comes from its contact with the underlying substrate.

When these "lines" experience any stress change (such as the pressure of a stylus or fingerprint ridge), the charge will be generated - the higher the stress, the more the charge, and the higher the brightness. The electroluminescent signal is processed and then both the shape and pressure gradients can be determined.

According to reports, this piezoelectric LED array can sense the pressure within a few milliseconds and then recover within a few milliseconds. The current resolution of the technology is as high as 6,300 dots per inch, but researchers believe that the accuracy can be improved by making smaller "lines".

A research paper was published in the Nature Photonics magazine published yesterday.