Mechanically gated data display via synergizing the mechanochromism of chiral photonic elastomers and optically responsive molecules

Abstract

Mechanochromic fluorophores and elastomers gain great potential in dynamic data encryption and anti-counterfeiting due to their instant responses, excellent handleability, high-throughput data-verification, and multi-dimensional security features. However, the reported mechanochromic fluorophores generally require solvent fuming or thermal annealing to revert their responses, sacrificing the handleability and lengthening the authentication time. For the mechanochromic elastomers, the data input requires precisely control the dose of the crosslinkers or phase tuning agents, making the high-throughput data-processing rather challenging. Here we developed a mechanically gated data display by synergizing the mechanochromism of chiral photonic elastomers and optically responsive molecules. Specifically, the reflectance or emission of the dyes/fluorophores could be selectively reflected or transmitted by the elastomers with desired photonic bandgaps, leading to data displays of given color/fluorescence. Mechanically stretching the elastomers can readily tuning their photonic bandgaps over a wide range, thereby notably alternating the corresponding reflection and emission wavelength, and the outcome of displayed data. Relaxing the elastomers rapidly restores the initial data. Moreover, the displayed data varies notably under L- and R-circular polarizer filter, respectively, offering good programmability and multi-dimensional security features. This work represents a unique data protection approach and enables properties unattainable by conventional mechanochromic fluorophores and elastomers.