Characterizing and predicting the self-folding behavior of weft-knit fabrics

Abstract

Self-folding behavior is an exciting property of weft knit fabrics that can be created using just front and back stitches. This behavior is easy to create, but not easy to anticipate and currently cannot be predicted by existing computer aided design (CAD) software that controls the CNC knitting machines. This work identifies the edge deformation behaviors that lead to self-folding in weft knits, and methods to characterize the mechanical forces driving these behaviors with regard to chosen manufacturing parameters. With this data and analysis of the fabric deformations, the self-folding behavior was purposely controlled using calculated scaling factors. Furthermore, theoretical equations were developed to mathematically predict these scaling factors, minimizing the trial and error required to design with self-folding behavior and create textiles with novel engineered properties. By understanding the mechanisms responsible for creating these threedimensional self-folding textiles, they can then be designed in a programmable manner for use in technical applications.