ScholarWorks@중앙대학교

초록

This study aimed to create wing-shaped multilayer tapping vibrators (W-MTV) that tap the human skin in a bending motion, reconstructing vibrotactile sensation on upper limb amputees. Composed of 4 layers of relaxor ferroelectric polymer (RFP), the W-MTV operates at a natural frequency of approximately 200 Hz, generating large vibrations (710 mu m amplitude, 4.25 g acceleration) through resonance. When a high electric field is applied, the electrostrictive deformation of RFP film results in bending deformation causing the W-MTV to flap and tap the skin, producing a localized vibrotactile sensation. In addition to vibrotactile stimulators, transcutaneous electrical nerve stimulators (ES) and thermal stimulators (TS) were developed to enhance object identification and discrimination. A flexible haptic patch, combining vibrotactile, electrotactile, and thermal stimulators, was fabricated to provide diverse tactile feedback. The combination of these stimuli selectively activates mechanoreceptors, helping amputees perceive texture, temperature, and surface stiffness. A driving algorithm and circuit were developed to generate tactile signals with specific waveforms, frequencies, and amplitudes, tailored to W-MTV, ES, and TS. For clinical tests, a flexible haptic patch and a prosthetic arm equipped with touch sensors, a temperature sensor, and a camera were integrated into the amputee's upper limbs. The amputees could accurately identify key surface properties such as stiffness (hard or soft), texture (flat or rough), and warmth (hot or cold) based on feedback from the W-MTV, ES, and TS, respectively. These results demonstrate the effectiveness of the haptic patch in replicating complex tactile sensations, enabling amputees to interact more accurately with their environment.

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