Design and Experiments of Biomimetic Stubble Cutter

The fore claws of the nymph of Cryptotympana atrata have excellent ability to cut and dig soil. Inspired by this, we designed a biomimetic stubble cutter to reduce the cutting resistance. Reverse engineering and 3D print technology were applied to design the biomimetic stubble cutter. Two types of biomimetic corn stubble cutters with different tooth heights (5 mm and 2.5 mm) were designed. The cutting ability of biomimetic corn stubble cutters was compared to the conventional design by the quadratic regression orthogonal test. Tooth height, dip angle of cutting edge, and cutting velocity were chosen as orthogonal test factors. The biomimetic stubble cutters show lower cutting resistance than the conventional one. Cutting velocity exerts the least effect on cutting resistance, followed by tooth height and dip angle of cutting edge. Optimal combination with the least cutting resistance is tooth height of 2.5 mm and dip angle of cutting edge of 40° while the cutting resistance does not vary remarkably with cutting velocity. Test results indicate the serrated structure design as a principal factor for cutting resistance reduction. The biomimetic stubble cutter design, inspired by the soil-cutting mechanism of Cryptotympana atrata nymph, remarkably improves the performance of stubble cutter.