A Biomimetic Fingerprint Improves Spatial Tactile Perception

The function of the human fingertip has been often debated. There have been studies focused on how the fingerprint affects the perception of high temporal frequencies, such as for improved texture perception. In contrast, here we focus on the effects of the fingerprint on the spatial aspects of tactile perception. We compare two fingertips, one with a biomimetic fingerprint and the other having a smooth surface. Tactile data was collected on a sharp edged stimulus over a range of locations and orientations, and also over a smooth (cylindrical) object. The perceptual capabilities of both (fingerprint and smooth) sensor types were compared with a probabilistic classification method. We find that the fingerprint increases the perceptual acuity of high spatial frequency features (edges) by 30–40% whilst not influencing the tactile acuity of low spatial frequency features (cylinder). Therefore the biomimetic fingerprint acts as an amplifier of high spatial frequencies, and provides us with evidence to suggest that the perception of high spatial frequencies is also one of the functions of the human fingertip.