Researchers led by the University of California San Diego have developed a soft, stretchy electronic device that can simulate the sensation of pressure or vibration when worn on the skin. This device Science RoboticsThis means we are one step closer to creating tactile technology that can reproduce more diverse and realistic tactile sensations.
The device consists of soft, stretchy electrodes attached to a silicone patch. It can be worn like a sticker on the fingertip or forearm. The electrodes, which are in direct contact with the skin, are connected to an external power source via wires. By sending a weak current through the skin, the device can generate a sensation of pressure or vibration, depending on the frequency of the signal.
“Our goal is to create a wearable system that can convey a wide range of tactile sensations using electrical signals without causing pain to the wearer,” said study co-first author Rachel Blau, a postdoctoral researcher in nanoengineering at UC San Diego’s Jacobs School of Engineering.
Existing techniques for reproducing touch through electrical stimulation often cause pain because they use rigid metal electrodes that do not fit well with the skin. The gap between these electrodes and the skin can cause painful electrical currents.
To address these issues, a team led by Blau and Darren Lipomi, a professor of chemical and nanoengineering at the University of California, San Diego, developed a soft, flexible electrode that adheres perfectly to the skin.
The electrodes are made of a new polymer material composed of components from two existing polymers. PEDOT:PSS, a conductive, hard polymer, and PPEGMEA, a soft, stretchy polymer. “By optimizing these ratios, [polymer building blocks]“We molecularly engineered a material that is both conductive and stretchable,” Blau said.
The polymer electrodes are laser-cut into a spring-like concentric design and attached to a silicon substrate. “This design enhances the elasticity of the electrodes and ensures that the current is targeted to a specific location on the skin, providing localized stimulation and preventing pain,” said Abdal, a Ph.D. student in mechanical and aerospace engineering at UC San Diego and the other co-author of the study. Abdal and Blau worked with UC San Diego nanoengineering undergraduates Yi Qie, Anthony Navarro, and Jason Chin to synthesize and fabricate the electrodes.
In the test, 10 participants wore electrode devices on their forearms. Working with behavioral scientists and psychologists at the University of Amsterdam, the researchers identified for the first time the lowest level of electrical current that can be detected. The frequency of the electrical stimulation was then adjusted so that participants experienced sensations categorized as pressure or vibration.
“We found that as we increased the frequency, participants felt more vibration than pressure,” Abdal said. “This is interesting because, biophysically, we didn’t know exactly how the electric current was perceived by the skin.”
The new insights could pave the way for the development of advanced haptic devices for applications such as virtual reality, medical prosthetics, and wearable technology.
Additional information:
Rachel Blau et al., Conductive block copolymer elastomers and psychophysical threshold setting for precise haptic effects; Science Robotics (2024). DOI: 10.1126/scirobotics.adk3925
Provided by University of California – San Diego
Summons: Soft, stretchy electrodes simulate the sense of touch using electrical signals, retrieved June 29, 2024, from https://phys.org/news/2024-06-soft-stretchy-electrode-simulates-sensations.html (2024 June 28, 2012).
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