Self-Folding of Pre-Strained Polymer Sheets Via Light

Self-folding is a self-assembly process that causes a predefined 2D template to fold into a desired

3D structure with high fidelity.1 Self-folding can be applied in the fields of actuation, sensors, and

packaging. We have developed a simple method of self-folding that uses pre-defined ink “hinges”

printed onto pre-stressed polymer sheets via a desk top printer. The ink absorbs external light,

causing the area underneath the hinge to heat up and relax the strain in the hinge regions gradually

across the sheet thickness. This process results in folding the sheet at the hinge region. We will

demonstrate that sequential folding of multiple hinges on the same sample can be programmed by

changing the light source and ink color of the hinge. We have successfully employed this strategy to

produce complex origami shapes.

References

1. T.G. Leong, A.M. Zarafshar, D.H. Gracias, Small, 2010, 6, 792.