Prevost Alexis, Scheibert Julien, Debrégeas Georges
Laboratoire de Physique Statistique; ENS, Universités Paris 6 & Paris 7, CNRS, Paris, France.
Commun Integr Biol. 2009 Sep;2(5):422-4. doi: 10.4161/cib.2.5.9052.
In humans, the tactile perception of fine textures is mediated by skin vibrations when scanning the surface with the fingertip. These vibrations are encoded by specific mechanoreceptors, Pacinian corpuscules (PCs), located about 2 mm below the skin surface. In a recent article, we performed experiments using a biomimetic sensor which suggest that fingerprints (epidermal ridges) may play an important role in shaping the subcutaneous stress vibrations in a way which facilitates their processing by the PC channel. Here we further test this hypothesis by directly recording the modulations of the fingerpad/substrate friction force induced by scanning an actual fingertip across a textured surface. When the fingerprints are oriented perpendicular to the scanning direction, the spectrum of these modulations shows a pronounced maximum around the frequency v/lambda, where v is the scanning velocity and lambda the fingerprints period. This simple biomechanical result confirms the relevance of our previous finding for human touch.
在人类中，用指尖扫描表面时，精细纹理的触觉感知是由皮肤振动介导的。这些振动由位于皮肤表面下方约2毫米处的特定机械感受器——环层小体（PCs）进行编码。在最近的一篇文章中，我们使用一种仿生传感器进行了实验，结果表明指纹（表皮嵴）可能在塑造皮下应力振动方面发挥重要作用，其方式有助于PC通道对其进行处理。在这里，我们通过直接记录在有纹理的表面上扫描实际指尖时所引起的指腹/基底摩擦力的调制，进一步检验这一假设。当指纹垂直于扫描方向时，这些调制的频谱在频率v/λ处显示出明显的最大值，其中v是扫描速度，λ是指纹周期。这个简单的生物力学结果证实了我们之前关于人类触觉发现的相关性。
