# Highly Efficient Color Tuning of Lithium Niobate Nanostructures on Flexible Substrate

## TL;DR

Researchers developed a flexible nanostructure that can efficiently change colors by stretching, with potential applications in wearable tech and sensing.

## Contribution

A novel stretchable color modulation method using lithium niobate nanostructures on PDMS for broad spectral tuning and polarization response.

## Key findings

- The structure achieves a maximum wavelength shift of nearly 180 nm through geometric optimization.
- The design effectively responds to different polarization waves and changes in refractive index.
- The method shows promise for flexible electronics, color generation, and biochemical sensing.

## Abstract

Nanostructures based on flexible material are essential for modulating reflected colors by actively changing the unit structure. However, current nanostructures face challenges in achieving active and efficient modulation across a broader spectral range. Here, we propose a stretchable color management method. The structure consists of a polydimethylsiloxane (PDMS) flexible substrate and cross-shaped lithium niobate (LiNbO3). This study achieves reflection color changes, continuous adjustment, and automatic switching of solar spectrum reflectance by optimizing the geometric structure. It shows that the spectral tuning range is larger, benefiting from the special nanostructures and the stretchability of PDMS, which result in a larger tunable period range and a maximum wavelength shift of nearly 180 nm. Moreover, this unique design has been effectively balanced and optimized to respond to different polarization waves. Finally, the sensing characteristics of the nanostructure are studied through its response to changes in the refractive index (RI). The results demonstrate a method with implications for flexible electronic devices, color generation, and biochemical sensing, contributing to progress in flexible wearable technology and green building.