University develops wireless, soft e-skin that can detect and deliver touch

University develops wireless, soft e-skin that can detect and deliver touch
A research team led by City University of Hong Kong (CityU) has developed a wireless, soft e-skin that can both detect and deliver the sense of touch, and form a touch network allowing one-to-multiuser interaction.

While there are haptic interfaces in the market to simulate tactile sensation in the virtual world, they provide only touch sensing or haptic feedback. The e-skin can perform self-sensing and haptic reproducing functions on the same interface.

The e-skin contains 16 flexible actuators in a 4x4 array, a microcontroller unit (MCU), a Bluetooth module and other electronics on a flexible circuit board. All the components are combined in a 7x10cm, 4.2mm-thick skin-patch-like device.

The button-liked actuator serves as the core part of the e-skin. Each of the actuators consists of a flexible coil, a soft silicone support, a magnet and a thin polydimethylsiloxane (PDMS) film, which perform the touch sensing and haptic feedback functions based on electromagnetic induction.

Once the actuator is pressed and released by an external force, a current is induced to provide electrical signals for tactile sensation to a corresponding actuator in another e-skin patch. The deeper the sender presses, the stronger and longer the sensation generated on the other e-skin. The electrical signal generated from the actuators is converted to a digital signal by an analog-to-digital converter on the circuit board of the e-skin patch. The data is then transmitted to the actuators on another e-skin via Bluetooth.

When the signal is received, a current is induced to reproduce the haptic feedback on the receiver’s e-skin through mechanical vibration. The process can be reversed to deliver vibrations from the receiver’s e-skin to the corresponding actuator of the sender’s.

Although each actuator can perform only one task at a time, the rest of the 15 actuators on the e-skin can supplement each other and perform the sensing or haptic reproducing function, allowing the e-skin patch to achieve bidirectional touch transmission simultaneously.

The research team's next focus is on practical applications for people with visually impairment, who could wear the e-skin to gain remote directional guidance and read Braille messages.


The research findings were published in the scientific journal Science Advances under the title “Touch IoT enabled by wireless self-sensing and haptic-reproducing electronic skin”.

Pic Credit: © Li, D. et al.

Most Viewed