While most smartphones now have haptic feedback built into their screens, the whole screen buzzes, limiting the applications of the technology. A new touchscreen film, however, utilizes LEDs to only vibrate in specific areas.
In a regular smartphone or tablet, the vibrations are generated by a small motor. This is effective for tasks such as alerting users to incoming calls or messages. The vibrations are felt across the entire screen surface, though – they can't emanate from precise locations within the display.
Scientists at South Korea's Electronics and Telecommunications Research Institute have set out to address this shortcoming, with a flexible display consisting of a touchscreen film laid over a grid of tiny low-power near-infrared LEDs. The film is coated with a polymer that absorbs light energy, converts it to thermal energy, then expands and bends due to the resulting heat.
When specific LEDs are made to rapidly blink on and off in a given area, the film over the top of those LEDs responds by rapidly bending and flattening as it alternately warms and cools. This action is felt by a user's fingertip as a localized vibration.
It is now hoped that once developed further, the technology could be put to use in applications such as changeable Braille displays for the blind, or onscreen images in which users can feel the differing textures of various materials.
The scientists are currently working on boosting the efficiency of the light-to-vibration conversion process, and on lowering the technology's energy requirements.
A paper describing the research was recently published in the journal ACS Applied Materials & Interfaces.
Source: National Research Council of Science & Technology via EurekAlert
