Research on the friction regulation of biomimetic multi-layer setal arrays under cooperative deformation effects

Biological setal arrays exhibit a complex multi-layer arrangement, allowing for friction behavior regulation through cooperative deformation of the setae. To reveal the friction regulatory mechanism of multi-layer setal arrays under cooperative deformation, this study established friction analytical models and validated the theoretical results through biomimetic experiments. First, for sliding on a smooth surface, under applied displacement, the continuous large deflection deformation of multi-length setae results in faster friction reduction and better multi-stage load-bearing capacity. Then, for sliding on a rough surface, the cooperative deformation of multi-length setae arranged in different directions can reduce fluctuations in the apparent friction and support force curves of the array after force superposition. Compared with single-layer arrays, multi-layer setal arrays demonstrate superior friction regulation. By adjusting the setal length ratio, number of layers, and distance, both the friction and load-bearing performance can be further optimized. This study offers insights for designing biomimetic surfaces with controllable friction.