3D structures with auxetic material behaviour for the production of novel, foam-free and curved textiles for energy absorption

Objective

Auxetic materials offer unique advantages due to their negative Poisson’s ratio: they expand perpendicular to the applied force rather than contracting – making them ideal for energy absorption, impact protection and lightweight construction. However, to date they have mostly been used in two dimensions, even though their full potential is only realised in 3D structures. In view of increasing raw material shortages and the need for high-performance, sustainable materials, the project aims to develop three-dimensional auxetic textiles that combine surface-area impact protection with material efficiency – without foams, but with improved mechanical properties.

Approach and results

Hybrid solutions (3D printing + knitting, joined by gluing/sewing/welding) and purely textile knitted fabrics with auxetic patterns have been developed for auxetic protective structures. The knee pad demonstrator uses flexible knitted fabrics for drapability and non-stretch layers (scale armour principle) for impact absorption. Auxetic stretching improves energy absorption – ideal for multidirectional movements.

Result: Both approaches offer functional protection, but challenges remain regarding long-term stability, comfort and lateral impact absorption. Further testing is required to evaluate performance against conventional knee pads. However, the solutions show great potential for flexible, sustainable protective applications in workwear and sportswear.