Prof. Rajadurai Chandrasekar, FASc., FNASc., FRSC, and his research team (M. Rohullah, Dr. V. V. Pradeep and S. Shurti) have published a seminal paper in Mechanophotonics, entitled “Mechanically controlled multifaceted dynamic transformations in twisted organic crystal waveguides” in Nature Communications 15, Article number: 4040 (2024). The impact factor of the journal is 16.60.

Their study introduces mechanically induced rare phenomena such as standing, leaning, stacking, and interlocking behaviors in naturally twisted optical waveguiding microcrystals on a substrate. The self-assembled microscale twisted crystal is flexible and emits orange fluorescence. Mechanistic analysis reveals the strain generated by the intergrowing orientationally mismatched nanocrystallites is responsible for the twisted crystal growth. Through a systematic process involving step-by-step bending and subsequent optical waveguiding experiments at each bent position, a linear relationship between optical loss and mechanical strain is established. Additionally, the vertical standing and leaning of these crystals at different angles on a flat surface and the vertical stacking of multiple crystals reveal the three-dimensional aspects of organic crystal waveguides, introducing light trajectories in a 3D space. Furthermore, the integration of two axially interlocked twisted crystals enables the coupling of polarization rotation along their long axis. These crystal dynamics expand the horizons of crystal behavior and have the potential to revolutionize various applications, rendering these crystals invaluable in the realm of crystal-related science and technology.

In this work, M. Rohullah and Dr. V. V. Pradeep (PhD students) have equal contributions. Shruti Singh worked on this project and performed preliminary studies for her master’s thesis.

Prof. R. Chandrasekar thanks SERB, New Delhi (SERB-STR/2022/00011 and CRG/2023/003911) for their continuous research funding.

Last year, Prof. R. Chandrasekar along with his collaborator P. K. Iyer (IIT G) published a paper entitled “Highly Efficient Color-Tunable Organic Co-crystals: Unveiling Polymorphism, Isomerism, Delayed Fluorescence for Optical Waveguides and Cell-imaging” in the same journal [Nat. Commun., (2023), 14, Article number: 6648].