Development of woven TSA fabric module for hand assistive gloves

Abstract

Wearable assistive gloves often present a trade-off between mechanical assistance and wearability due to bulky, externally mounted actuation systems. This study developed a textile-integrated hand assistive glove by structurally embedding twisted string actuator (TSA) tendon strings into a woven fabric module and evaluated how the textile module influenced assistance performance and user acceptance. By comparing two woven structures (1/1 plain and 3/1 twill), the plain weave structure was selected based on warp-direction mechanical requirements for TSA-driven actuation. Woven modules were fabricated with different weave densities, and a 6 ends-per-inch (epi) configuration was adopted to balance force transmission and frictional resistance during rotational TSA operation. Two module shapes were applied: a flat-type module that is attached to the palmar fingertip and a round-type module enclosing the fingertip in a tapered thimble form. Ten adult male participants evaluated the gloves under four conditions (flat-type, round-type, commercial pneumatic glove, and bare hands). Design perception was assessed using eye tracking and design related questionnaires, assistance performance was evaluated using surface electromyography (sEMG) during a 12 kg static holding task, and wearability was examined using electroencephalography (EEG), clothing pressure, and subjective questionnaires during repetitive object-handling tasks. The sEMG results normalized to the bare-hand reference showed reduced muscle activation for the round type (74.14% RVC) and flat type gloves (85.26% RVC), whereas the pneumatic glove showed a slight increase (105.92% RVC). EEG results did not differ significantly across conditions, while clothing pressure differed across glove types, with the pneumatic glove exhibiting the highest mean pressure. Despite generating higher clothing pressure than the flat type glove, the round type glove received higher ratings for perceived functionality and purchase/use intention, indicating that wearability is not determined solely by physical pressure but is influenced by perceived functional effectiveness. The findings demonstrate that woven module shape plays a decisive role in balancing mechanical assistance and user acceptance, providing experimentally grounded design guidelines for textile-integrated assistive gloves.