Professor Soo Seok Choi's research team, comprising Electrical Engineering master's student Chaehyeon Kwon and doctoral students Seungmin Nam and Sanghyeon Han, has been selected for the inside back cover of the prestigious interdisciplinary journal Advanced Functional Materials (IF 19).

The team was the first to realize, in a three-dimensional multistretchable environment spanning the X, Y, and Z axes, the optical transformation mechanism of helical chiral nanostructures that change color wavelengths by adjusting nanoscale lengths under flexible stretching conditions. The study precisely identified the mechanisms of the resulting nano-optical changes.

Stretchable electronic devices and stretchable color control are envisioned as transformative flexible technologies. Worldwide interest is growing rapidly because of their potential to surpass existing technologies and their applications in sensors, semiconductors, displays, electronic skin, encryption, electromagnetic-wave control, communications, and fashion. However, stretching the wavelengths that determine color poses the difficult challenge of precisely understanding and controlling dimensions on the nanometer scale corresponding to optical wavelengths.

Moving beyond the simple uniaxial stretching studied in most existing stretchable technologies, this work accurately understands and implements stretching across all three axes in a truly flexible environment. By identifying precise optical properties and nanostructural change mechanisms, it makes a significant contribution to extending stretchable technology from one dimension to three. Various follow-on studies are anticipated.

The research was supported by the Samsung Science & Technology Foundation and a stretchable technology demonstration project of the Korea Evaluation Institute of Industrial Technology.