Auxetic Meta-Display: Stretchable Display without Image Distortion

Mechanical metamaterials possess unusual mechanical properties that cannot be found in nature. Auxetic metamaterials have negative Poisson's ratios and tend to expand in a direction perpendicular to the axial extension direction. When the Poisson's ratio of a display circuit board is forced to be -1 by adopting an auxetic metamaterial, a display can be stretchable without image distortion, and this display is called a meta-display in this study. The critical obstacles to implementing a stretchable display are large stretchability, high deformation uniformity, and low image distortion. The meta-display overcomes these obstacles by incorporating micro-LEDs and a kirigami-based auxetic circuit board. An auxetic meta-display with a stretchability of 24.5%, Poisson's ratio of -1, and no image distortion under uniaxial stretching is demonstrated. Finally, the roll transfer process enabled the scaling-up of a 3-inch meta-display attachable to surfaces with non-zero Gaussian curvatures. This conformity to the non-zero Gaussian curvature helps realize biomedical applications such as wearable display, phototherapy, and skincare.

Automated summary

Mechanical metamaterials, especially auxetic metamaterials with negative Poisson's ratios, allow for stretchable displays without image distortion. The meta-display, incorporating micro-LEDs and a kirigami-based auxetic circuit board, overcomes the challenges of large stretchability, high deformation uniformity, and low image distortion. It demonstrates a stretchability of 24.5%, Poisson's ratio of -1, and no image distortion under uniaxial stretching.