On-Skin Wireless Vibratory Interfaces by Stretchable Multilayer Circuits

Abstract

Emerging technologies in soft electronics are facilitating seamless interactions with the human body's neural network. Among various sensory modalities, vibratory stimulation offers distinct advantages as a feedback strategy in wearable and implantable systems. However, existing devices face challenges of limited battery life, noncompliant device architecture, and complicated circuit designs, particularly for devices requiring adaptive fitting to various curved surfaces of the human body. In this study, we present a wireless and stretchable electronic device with multilayer circuits using elastic and printable metallic inks. The wireless vibratory interfaces were designed with a compact and soft circuit, which directly converts electromagnetic power to produce vibrotactile stimulation. Patterns of the mechanical vibration were highly programmable by frequency-shift keying (FSK) modulation of the input signals. The wireless and soft vibratory interfaces have excellent mechanical compliance, maintaining their functionalities under large deformations. Together with a fabric signal transmitter fabricated from elastic conductive fibers, we demonstrate a smart and interactive on-skin device, which translates spatial information into perceptible tactile cues to navigate visually impaired users through unstructured environments. The developed device holds significant promise for applications in sensory substitution, human-machine interfaces, and biomedical treatments.