Sub-surface Skin Deformation in Response to Gentle Brushing

TL;DR

This study visualizes internal skin strains caused by gentle brushing using high-speed fOCT, revealing layer-specific responses that could influence tactile perception and sensory processing.

Contribution

It introduces a novel high-speed fOCT method to observe sub-surface skin deformation in response to tactile stimuli, providing new insights into skin mechanics.

Findings

Different skin layers respond uniquely to brushing stimuli.

Internal skin dynamics are likely involved in tactile perception.

The method enables detailed analysis of skin's mechanical response.

Abstract

Even simple tactile stimuli can lead to remarkably different perceptions among individuals, both in intensity and pleasantness. To understand the physical factors behind this variation, it is important to investigate how mechanical events are transmitted through the skin. In this study, we visualize the internal skin strains in response to soft brushing stimuli using functional Optical Coherence Tomography (fOCT), which provides depth-resolved time-series data of the displacement of the skin. Driven with custom-made software, the system enabled sub-surface imaging at a refresh rate of 10 kHz. Brushing was applied to the back of the hand, and skin displacement was observed at different depths. The results show that each skin layer responds differently to the stimulus, suggesting that internal skin dynamics play a role in tactile perception. This method offers a way to investigate how mechanical events within the skin relate to sensory function.