Zero-Poisson Ratio Elastomeric Substrates for Distortion-Free Stretchable Displays
Stretchable displays are critical for emerging wearable electronics, soft sensors, and next-generation AR/VR interfaces. Although recent advances have enabled foldable, twistable, and rollable displays, intrinsically stretchable substrates often exhibit significant lateral contraction under tensile strain due to their high Poisson ratio, leading to unintended wrapping, distortion, and shrinkage. Here, we report a transparent heterogeneous-modulus elastomeric substrate designed to achieve near-zero Poisson ratio while maintaining mechanical softness and optical transparency. The substrate consists of line-patterned hard polydimethylsiloxane (PDMS) embedded within a soft PDMS matrix, producing spatially heterogeneous strain distribution during stretching. In this architecture, the soft PDMS functions as a strain-absorbing medium, while the embedded hard PDMS patterns suppress lateral deformation perpendicular to the applied strain. As a result, the structure significantly dampens transverse contraction and realizes a near-zero effective Poisson ratio. To demonstrate the utility of this platform for stretchable optoelectronics, LED arrays were integrated onto the heterogeneous substrate. The devices exhibit minimal vertical and lateral distortion during tensile deformation, enabling mechanically stable operation of stretchable light-emitting displays. This heterogeneous modulus strategy provides a simple, scalable approach to mechanically robust stretchable display platforms.