2023-03-15 ミシガン大学
An array of different growth conditions, spanning from left-handed twists made with only left-handed cystine to flat pancakes made with a 50-50 mix to right-handed twists made only with right-handed cystine. The ability to control the degree of twist in a curling, nanostructured material could be a useful new tool in chemistry and machine vision. Image credit: Prashant Kumar, Kotov Lab, University of Michigan.
材料は、表面から反射される光の波の形状に情報をエンコードし、人間が読む符号の2D配列ではなく、偏光としてねじれた種類の円偏光光を優先的に反射する。研究は、自然光ではなくロボットによって生成される円偏光に頼ることで、ロボットが明るい環境や暗い環境でも信号を見落とすことが少なくなるようになることを示唆している。
＜関連情報＞
- https://news.umich.edu/for-the-first-time-controlling-the-degree-of-twist-in-nanostructured-particles/
- https://www.nature.com/articles/s41586-023-05733-1
キラリティ連続性を有する光活性「蝶ネクタイ」ナノアセンブリー Photonically active bowtie nanoassemblies with chirality continuum
Prashant Kumar,Thi Vo,Minjeong Cha,Anastasia Visheratina,Ji-Young Kim,Wenqian Xu,Jonathan Schwartz,Alexander Simon,Daniel Katz,Valentin Paul Nicu,Emanuele Marino,Won Jin Choi,Michael Veksler,Si Chen,Christopher Murray,Robert Hovden,Sharon Glotzer & Nicholas A. Kotov
Nature Published:15 March 2023
DOI:https://doi.org/10.1038/s41586-023-05733-1
Abstract
Chirality is a geometrical property described by continuous mathematical functions1,2,3,4,5. However, in chemical disciplines, chirality is often treated as a binary left or right characteristic of molecules rather than a continuity of chiral shapes. Although they are theoretically possible, a family of stable chemical structures with similar shapes and progressively tuneable chirality is yet unknown. Here we show that nanostructured microparticles with an anisotropic bowtie shape display chirality continuum and can be made with widely tuneable twist angle, pitch, width, thickness and length. The self-limited assembly of the bowties enables high synthetic reproducibility, size monodispersity and computational predictability of their geometries for different assembly conditions6. The bowtie nanoassemblies show several strong circular dichroism peaks originating from absorptive and scattering phenomena. Unlike classical chiral molecules, these particles show a continuum of chirality measures2 that correlate exponentially with the spectral positions of the circular dichroism peaks. Bowtie particles with variable polarization rotation were used to print photonically active metasurfaces with spectrally tuneable positive or negative polarization signatures for light detection and ranging (LIDAR) devices.
