The breakthrough in virtual reality delivers consistent tactile sensations, enhancing user interaction with digital environments.
A research team from the Institute for Basic Science’s Center for Nanomedicine, in collaboration with the Department of Neurosurgery at Severance Hospital, has developed a new virtual haptic technology. This innovation ensures that users experience uniform tactile sensations on displays.
Virtual haptic technology, or tactile rendering, uses methods and systems to simulate touch within a virtual environment. Designed to replicate the sensation of physical interaction with virtual objects, it allows users to experience textures, shapes, and forces as if they were tangible. This technology is increasingly employed in virtual reality (VR) and augmented reality (AR) settings, enhancing visual and auditory inputs to bridge the virtual and physical worlds more effectively.
Electrotactile systems represent a significant advancement in this field, moving away from traditional methods that rely on physical vibrations. These systems create tactile sensations through electrical stimulation, mimicking the function of mechanoreceptors—sensory cells in the skin that transmit touch information to the brain as electrical signals. By artificially generating these signals and fine-tuning parameters such as current density and frequency, electrotactile systems offer a range of precise and diverse tactile experiences.
Despite their potential, current electrotactile technologies face safety and consistency challenges, such as skin contact pressure fluctuations leading to inconsistent tactile sensations and safety risks associated with high electrical currents. The IBS research team has developed the Transparent Pressure-Calibratable Interference Electrotactile Actuator (TPIEA) to address these issues.
The TPIEA consists of two main components: an electrode section that generates electrotactile sensations and a pressure sensor that adjusts based on finger pressure. Researchers enhanced the electrode’s efficiency by applying platinum nanoparticles to an indium tin oxide-based electrode, significantly reducing impedance and achieving a high transmittance of about 90%. This ensures consistent tactile feedback regardless of the pressure applied to the display.
The research team conducted somatosensory evoked potential (SEP) tests to accurately measure and standardize tactile sensations, creating over nine distinct electrotactile sensations by adjusting electrical stimulation parameters. They also successfully integrated the Transparent Pressure-Calibratable Interference Electrotactile Actuator (TPIEA) into smartphone displays, allowing for the reliable production of complex tactile patterns. Additionally, they introduced interference phenomena into electrotactile technology, which significantly enhanced tactile resolution by about 32%, surpassing other technologies like the Teslasuit.
Reference: Kyeonghee Lim et al, Interference haptic stimulation and consistent quantitative tactility in transparent electrotactile screen with pressure-sensitive transistors, Nature Communications (2024). DOI: 10.1038/s41467-024-51593-2
