Auxetic microrods for vibration control: Toward next-generation shin guard design

This study explores the behavior of auxetic microrods—unusual structures that expand sideways when stretched—under torsional vibration. We examined triangular and elliptical forms using nonlocal strain gradient theory to capture the subtle effects that appear at very small scales. The analysis shows that shape, orientation, and boundary support all play a decisive role in how these rods respond. Although the work is grounded in mechanics, the findings translate readily into sports applications. Shin guards, for instance, face repeated, high-energy impacts where comfort and protection often pull in opposite directions. Traditional foams and plastics tend to pass sharp vibrations into the leg or wear out quickly. Auxetic microrods, by contrast, can spread the force of a strike, soften the shock, and extend the life of the gear—all without adding bulk. Incorporating these microscale structures could give athletes shin guards that are lighter, tougher, and more comfortable, marking a clear step toward smarter protective equipment.