Origami-inspired ring lets users 'feel' virtual worlds

 

Virtual reality (VR) and augmented reality (AR) are technologies that allow users to immerse themselves in digital worlds or enhance their surroundings with computer-generated filters or images, respectively. Both these technologies are now widely used worldwide, whether to experience video games and media content in more engaging ways or improve specific training and assist professionals in their daily tasks.

To date, VR and AR have primarily focused on what users see and hear, primarily improving the quality of digital experiences from a visual and auditory standpoint. The sense of touch, on the other hand, has been in great part overlooked.

Researchers at Sungkyunkwan University, École Polytechnique Fédérale de Lausanne and Istanbul Technical University recently developed a new wearable device that could allow users to also realistically "feel" tactile sensations aligned with what they are experiencing in a virtual world. This device, introduced in a paper published in Nature Electronics, is an origami-inspired ring that measures forces on a user's skin, pushing back onto the finger to produce specific sensations.

"Wearable human–machine interfaces could provide immersive, multisensory interactions, turning everyday items into smart haptic devices for virtual and augmented reality," wrote Sunju Kang, Mustafa Mete and their colleagues in their paper. "However, the development of tactile wearables with kinesthetic feedback remains limited by the size and weight of the devices, which restricts portability and comfort. We report a haptic ring that weighs 18 g and offers three-degrees-of-freedom force sensing and feedback."

A lightweight device for realistic touch in VR

The lightweight ring created by Kang, Mete and their colleagues is attached to a folded geometric structure that is inspired by the paper-folding art of origami. This structure allows the device to efficiently detect pressing and sliding forces on the skin, producing realistic tactile sensations accordingly.

"The system has an origami-inspired structural base that provides efficient and compact force transmission, and a soft force-sensing skin capable of simultaneously detecting shear and normal forces," wrote the authors. "The force-sensing skin is made by combining a topology-optimized, laser-patterned layer that has pyramid microstructures with a layer with four resistive pixels, an approach that ensures linear sensitivity and a rapid response time."

The team's newly developed haptic ring integrates four sensors that change their electrical resistance when they are pressed or bent, as well as soft pneumatic actuators, components that use air pressure to move the ring in ways that produce specific tactile sensations. To track the movements of a user's finger, the researchers used inkjet-printed flexible and bending sensors.

Creating increasingly realistic virtual experiences

In initial tests, the new haptic ring was found to apply forces in three degrees of freedom, delivering force feedback up to 6.5 newtons (N). This means that it could produce perceivable and realistic tactile experiences that are aligned with what users are experiencing in VR or AR.

In the future, the device developed by Kang, Mete and their colleagues could be improved further and deployed in various real-world settings, potentially enhancing gaming experiences, as well as professional training and medical rehabilitation practices. In addition, it could inspire the development of similar haptic devices that could pave the way for increasingly immersive and realistic digital experiences.