Researchers at UC San Diego have unveiled a revolutionary soft, stretchable electrode that can mimic touch sensations like pressure and vibration without causing pain. This innovation could significantly enhance haptic feedback in various fields, from virtual reality to medical prosthetics.
A groundbreaking development by researchers at the University of California San Diego promises to transform the way we experience touch through electronic devices. The team has created a soft, stretchable electrode that can replicate sensations such as pressure and vibration when applied to the skin, unveiling new horizons for virtual reality, medical prosthetics and wearable technology.
This innovative technology, detailed in the journal Science Robotics, involves a flexible electrode that adheres to the skin like a sticker. When connected to an external power source, the device transmits gentle electrical currents through the skin, evoking tactile sensations without causing discomfort. Traditional methods often cause pain due to rigid metal electrodes that do not conform well to the skin, leading to painful currents. In contrast, this new electrode is designed to eliminate these issues.
Credit: Liezel Labios/UC San Diego Jacobs School of Engineering
“Our goal is to create a wearable system that can deliver a wide gamut of touch sensations using electrical signals—without causing pain for the wearer,” Rachel Blau, co-first author and nano engineering postdoctoral researcher at the UC San Diego Jacobs School of Engineering, said in a news release.
The core of this breakthrough lies in the electrode’s construction. By combining two polymers — conductive PEDOT:PSS and stretchy PPEGMEA — the researchers developed a material that is both conductive and flexible. Laser cutting the polymer into a spring-shaped, concentric design further enhances its stretchability, ensuring that the electrical current precisely targets specific skin areas, thus providing localized stimulation without pain.
“This design enhances the electrode’s stretchability and ensures that the electrical current targets a specific location on the skin, thus providing localized stimulation to prevent any pain,” Abdulhameed Abdal, a doctoral student and co-first author from the Department of Mechanical and Aerospace Engineering at UC San Diego, said in the news release
In experiments, 10 participants wore the electrode on their forearm, experiencing controlled levels of electrical stimulation. Collaboration with behavioral scientists from the University of Amsterdam allowed the researchers to fine-tune the device’s frequency settings to elicit pressure or vibration sensations.
“We found that by increasing the frequency, participants felt more vibration rather than pressure,” Abdal added, providing new insights into how the skin perceives electrical currents.
The implications of this discovery are vast. Enhanced haptic feedback systems could lead to more immersive virtual reality experiences, more sensitive and realistic medical prosthetics, and advanced wearable tech that interacts seamlessly with human touch.
This pioneering work, titled “Conductive Block Copolymer Elastomers and Psychophysical Thresholding for Accurate Haptic Effects,” included contributions from UC San Diego undergraduates and faculty, with the support of the National Science Foundation and the San Diego Nanotechnology Infrastructure. The research underscores the profound potential of innovative material science in enhancing human-computer interactions, making future technology more intuitive and responsive to the human touch.