The National Research Foundation of Korea (NRF) has announced that Professor Jin Woo Bae (Corresponding Author, Korea University of Technology and Education, KOREATECH) and Seung-Ju Oh (First Author, Korea University of Technology and Education, KOREATECH) have developed a novel ultra-stretchable, transparent, and water-resistant all-in-one electrochromic device using a non-aqueous polyvinyl chloride (PVC)-based ionogel. The proposed device can easily stretch, twist, and fold.

Electrochromic devices have a wide range of applications in next-generation transparent displays due to their low driving voltage, large transmittance change, and high color efficiency. Initially, hydrogel-based electrochromic devices were developed; however, their performance deteriorates over time due to evaporation and electrolyte leakage depending on ambient conditions.

To overcome this issue, non-aqueous polymer gel electrolyte-based electrochromic devices have been developed, demonstrating stable performance over prolonged periods. Commonly used polymer electrolytes include polyvinylidene fluoride-co-hexafluoropropylene and PVDF-co-HFP. Despite better performance, PVDF-based polymer electrolytes are unsuitable for stretchable applications due to their rigidity.

Addressing this concern, our research group has developed a novel ultra-stretchable, transparent, and water-resistant electrochromic device using a non-aqueous polyvinyl chloride (PVC)-based ionogel. This device is not only easily stretchable, twistable, and foldable, but also maintains its original shape and structure over extended periods, regardless of ambient conditions. Furthermore, by directly incorporating transparent and stretchable electrodes into the electrochromic device, we have successfully created an ultra-stretchable and bendable electrochromic device.

This research has enabled the realization of a stretchable electrochromic device with high stretchability and color stability through a simple structure and facile fabrication process. The proposed device is expected to find applications in various fields, including next-generation wearable devices such as e-skin, smart clothes, smart camouflage, and stretchable transparent displays.

This work was supported by the BK-21 FOUR program through the National Research Foundation of Korea (NRF) under the Ministry of Education and the National Research Foundation of Korea (NRF) (2021R1A2C2011898) under the Ministry of Science and ICT (MIST).

[Reference] Oh, S. J., & Bae, J. W. (2023) “All-in-One plasticized Ionogel-based stretchable electrochromic devices.” Chemical Engineering Journal. https://doi.org/10.1016/j.cej.2023.143367 

[Main Author] Seung-Ju Oh(Korea University of Technology and Education, KOREATECH), Jin Woo Bae(Korea University of Technology and Education, KOREATECH)

* Contact : jwbae@koreatech.ac.kr