Wearable Haptics for Orthotropic Actuation Based on Perpendicularly Nested Auxetic SMA Knotting

Authors: Mannan Khan, Saewoong Oh, Tae‐Eun Song, Wonhee Ji, Manmatha Mahato, Yang Yang, Daniel Saatchi, Syed Sheraz Ali, Jaewoo Roh, Donghyeok Yun, Jee‐Hwan Ryu, Il‐Kwon Oh

Published: 2024-10-29

DOI: 10.1002/adma.202411353

Source: Full article


Abstract

AbstractSmart wearable tactile systems, designed to deliver different types of touch feedback on human skin, can significantly improve engagement through diverse actuation patterns in virtual or augmented reality environments. Here, a perpendicularly nested auxetic wearable haptic interface is reported for orthotropically decoupled multimodal actuation (WHOA), capable of producing diverse tactile feedback modes with 3D sensory perception. WHOA incorporates shape memory alloy wires that are intricately knotted into an auxetic structure oriented along orthotropic dual axes. Its perpendicularly nested auxetic structure enables orthotropic actuation, allowing independent expansion and contraction along both x and y‐axes, as confirmed by force‐strain and displacement‐time performance tests. Additionally, the perylene coating provides orthogonal electrical isolation to WHOA, allowing for stripe‐specific localized actuation and enabling multiple tactile feedback modes. As an orthotropic wearable haptic interface, WHOA distinguishes between x‐axis and y‐axis directions and ultimately delivers multi‐dimensional information regarding movements in 3D space through tactile feedback. As a result, when worn on the foot or arm, WHOA naturally delivers spatiotemporal tactile information to the user, facilitating navigation and teleoperation with 3D sensory perception.