3D Printed Spacer Fabrics

Spacer fabrics are three-dimensional textiles composed of two fabric layers and a filler yarn that connects the outer layers, while maintaining some distance between them. Spacer fabrics are favorable thanks to their soft, breathable, and elastic properties. Indeed, they are prevalent in a variety of products such as bags, footwear, and protective equipment. Spacer fabrics are usually knitted on large and expensive double-needle bar warp knitting machines. These machines can produce spacer fabrics in a variety of thicknesses, patterns, and densities. However, they are limited in their potential to modulate these parameters within a single knitted fabric. Our goal is to develop a non-uniform 3D printed metamaterial analogous to knitted spacer fabrics, which we refer to as 3D Printed Spacer Fabrics (3DSF). We produce these fabrics using desktop 3D printers and off-the-shelf Thermoplastic Polyurethane (TPU) filament. 3DSF exhibits nonlinear compression behavior due to the construction of the filler strands between the faces. We provide a design tool that enables controlling different geometry and printing parameters of the 3DSF, for tuning the dimensions, appearance, and compression of the material. To evaluate how the different parameters affect the compression behavior, we conduct a series of compression tests. The results show that the compression behavior can be tuned to fit specific applications. Finally, we suggest two use cases: biker shorts and a knee pad that uses the 3DSF for padding.