Schematic of the neural tactile detection system and the three corresponding stimulation modes. Exploded view illustration of a device with 16 independently controlled multimodal haptic feedback units, each unit having a mechanical actuator (MA), two pairs of thermoelectric (TE) pads, and a pair of electrotactile electrodes (ES). Credit: Huang et al.
Virtual reality (VR) and augmented reality (AR) technologies have become increasingly advanced over the past decade, enabling highly engaging gaming experiences and new forms of multimedia entertainment. Yet there is still much to be done, particularly in terms of artificially stimulating other senses beyond vision and hearing.
Researchers from the City University of Hong Kong and other institutes in China attempted to develop new interfaces that would allow end users to closely connect to virtual environments through their sense of touch. In a recent article, published in Natural electronicsThey introduced a new haptic interface that delivers multi-dimensional tactile signals directly to the skin, eliciting realistic sensations that could further enhance virtual experiences.
“Currently, global research on flexible electronics mainly focuses on the development of flexible sensors, while research on flexible feedback techniques remains limited,” Ya Huang, co-author of the paper, told Tech Xplore.
“Recognizing the lack of feedback in flexible electronic technology, Professor Yu integrated flexible mechanical feedback actuators using flexible electronic technology, which made significant progress in this field. This innovation, presented for the first time in a Nature published in 2019, has found applications in areas such as social media, gaming, prosthetic control and feedback, and various biomedical fields.
Professor Xinge Yu, working at the City University of Hong Kong and the Hong Kong Science Park, has focused his recent work on the development of haptic interfaces based on flexible electronics. In 2022, his research group published an article in Intelligence of natural machines, introducing a new haptic interface for wireless electrostimulation. However, this article has mainly focused on creating overall haptic feedback using this interface, rather than generating various immersive tactile sensations.
“In our recently published paper, we filled this gap by designing a haptic feedback interface with multi-dimensional stimulation modes,” Huang explained. “This interface selectively stimulates different receptors, thus reproducing tactile sensations corresponding to various textures.”
The human body can perceive a wide range of tactile information when it physically encounters different objects or surfaces. This ability is supported by biological mechanisms that allow humans to process many types of tactile information.
“These multidimensional signals work in harmony, giving us a diverse and vivid tactile experience,” Huang said. “Providing a feedback interface capable of delivering multi-dimensional tactile signals plays a crucial role in optimizing the effective reproduction of human tactile sensation in VR/AR. Our device offers a significant advantage by integrating three feedback modes into a single skin-integrated device. interface.”
How the multimodal haptic patch works. a, Illustration of the idea that users can experience sensations of real objects using our haptic feedback interface in VR. Photographs of different haptic feedback unit arrays, including the 2×4 patch (b), the 4×4 patch (c), and the palm-shaped patch (d). e, 3D graph of wireless control circuits. Credit: Huang et al.
Huang and his colleagues introduced a new activation principle that allows their haptic system to stimulate different sensory receptors and sensory nerves in the human body. Combined with VR or AR technology, this could ultimately enable even more realistic and immersive experiences, enriched with tactile sensations.
Currently, technology designed to produce haptic feedback is expanding in two main directions. The former focuses on electrical stimulation, while the latter produces tactile signals via mechanical actuation.
“The most difficult aspect of electrical stimulation mainly focuses on biological research, aiming to precisely activate nerves to generate real tactile sensations in the human body,” Huang explained.
“Nevertheless, this area offers vast potential for theoretical exploration and progress. On the other hand, mechanical actuation makes it possible to obtain haptic feedback by designing deformable interfaces or interactive devices that reproduce the deformation of the surface of the skin when interacting with real objects.The main challenge here lies in designing the mechanical structure to accurately mimic the tactile experience.
Recent work by Huang and colleagues effectively bridges the gap between these two distinct approaches to producing haptic feedback. This is achieved via the introduction of a principle that demarcates the selective stimulation of different tactile receptors, based on the rules that underlie the distribution of these receptors and the activation of sensory nerves in the human body.
“By combining the advantages of electrical stimulation and mechanical actuations, we were able to achieve more diverse and immersive tactile feedback effects,” Huang said. “Our approach breaks down the barriers that previously separated these two paths, enabling the integration of multiple feedback modes within a single device. These rules of experimentation and innovation open up new possibilities to provide users with richer, more realistic tactile experiences.
The skin-integrated multimodal haptic interface developed by this team of researchers constitutes a major contribution to the research field focused on the development of haptic technology. In the future, this work could open up exciting new possibilities for creating highly immersive VR content also accompanied by realistic tactile sensations.
“There is still a lot of room for development in the area of haptic feedback,” Huang added. “For the feedback interface itself, various research areas, such as materials synthesis, mechanical structure optimization and neuroelectrophysiology, are closely related to the design principles and manufacturing of the feedback interface When considering future applications, several aspects including VR software, machine algorithms, data processing and even user psychology present valuable avenues for exploration.
More information:
Ya Huang et al, A skin-integrated multimodal haptic interface for immersive tactile feedback, Natural electronics (2023). DOI: 10.1038/s41928-023-01074-z.
© 2023 Science X Network
Quote: A multimodal haptic interface integrated into the skin to produce immersive tactile experiences (December 21, 2023) retrieved on December 21, 2023 from
This document is subject to copyright. Apart from fair use for private study or research purposes, no part may be reproduced without written permission. The content is provided for information only.
