Piezoelectric tech allows tactile sensations to be sent and received
Although there already are experimental "telehaptic" systems that allow people to send and receive tactile sensations, they tend to be rather bulky and awkward. A new one is much slimmer and thus more practical, thanks to the use of piezoelectric materials.
Created by scientists at South Korea's Electronics and Telecommunications Research Institute (ETRI), the system incorporates a device that is worn on the user's dominant hand. In a typical-use scenario, one such device would be worn by the person who was sending a sensation, while another would be worn by the recipient.
The prototype wearable currently takes the form of a small electronics board located on the back of the hand, which is hard-wired to a thin, flexible piezoelectric element that is applied like a sticker to the pad of the index finger. That element is less than 1 mm thick.
Piezoelectric materials produce an electrical current when they're subjected to mechanical stress or vibrations. This quality comes in handy (no pun intended) for the sender – as they move their element-clad fingertip across a textured surface, the resulting tiny vibrations are converted into electrical signals which are wirelessly transmitted to the recipient.
Another quality of piezoelectric materials then comes into play. Not only do they produce electricity when vibrated, but they also vibrate when subjected to an electrical current. This means that as the recipient's device receives the transmitted signal, its fingertip element vibrates, reproducing the sensation felt by the sender.
In tests conducted so far, the system was able to sense and reproduce the feeling of surfaces such as cotton, polyester, spandex and protruding lettering, along with the sensation of plastic rods being rolled on the fingertips. The signals were sent via Bluetooth up to a distance of 15 m (49 ft) with a lag time of just 1.55 milliseconds – the received signals matched the transmitted signals by about 97%.
Plans now call for the technology to be refined further, which could involve improving its tactile resolution, and allowing it to sense and reproduce the feelings of hot and cold.
"Through the light and flexible on-skin tactile reproduction device that can be attached to the skin, we have taken a step forward in preparing a foundation environment for developing highly immersive virtual/augmented reality content," said the lead scientist, Hye Jin Kim.
A paper on the research was recently published in the journal NPJ Flexible Electronics.