Last year we heard about an “electronic skin” developed at City University of Hong Kong, which delivers tactile sensations to wearers. The university has now gone one better, with an e-skin that both senses and reproduces users’ touches.
Currently in functional prototype form, the e-skin is actually more similar to the Epidermal VR system that City University helped develop back in 2019. Like that haptic setup, it incorporates a grid of flexible actuators embedded in a skin-patch-type device.
In the case of the new e-skin there are 16 such actuators arranged in a 4 by 4 array, along with a Bluetooth module, analog-to-digital converter and other electronics mounted on a flexible circuit board. The rectangular silicone patch itself measures 7 by 10 cm (2.8 by 3.9 in), and is 4.2 mm thick.
Each actuator is made up of a flexible coil, a soft silicone support, a magnet and a thin polydimethylsiloxane (PDMS) film. When the actuator is pressed and released by a finger – or anything else – it generates an electrical signal which is converted to a digital signal. The digital signal is then wirelessly transmitted via Bluetooth (and conceivably the internet) to another e-skin patch, on another person.
That patch responds by causing the corresponding actuator on itself to vibrate – the longer and harder the initial touch on the sending patch, the longer and stronger the vibrations on the receiving patch. And while each actuator can’t simultaneously detect and reproduce touches, the e-skin as a whole can, with some actuators detecting touches at the same that others are reproducing them.
Li, D. et al.
“Our e-skin can communicate with Bluetooth devices and transmit data through the internet with smartphones and computers to perform ultralong-distance touch transmission, and to form a touch Internet of Things (IoT) system, where one-to-one and one-to-multiple touch delivery could be realized,” said the lead scientist, Assoc. Prof. Yu Xinge. “This form of touch overcomes the limitations of space and greatly reduces the sense of distance in human communication.”
The scientists are also looking into adapting the technology for use by the blind, enabling them to feel Braille messages transmitted directly to their skin.
A paper on the research was recently published in the journal Science Advances.
Source: City University of Hong Kong
