Thermally controlled and undetectable active artificial skin, ranging from visible to infrared.
The extraordinary ability of cephalopods to hide in the background has prompted researchers to replicate their fascinating ability to camouflage in infrared (IR) and spectacular spectrum. Recent advances have provided a number of physical mechanisms for reproducing the hidden functionalities of cephalopods. However, most of the work focused only on visible camouflage or IR camouflage range: not double-mode single-device structures, which are visible in the right state and can be easily changed from IR mode.
Recently, Professor Seung hwan Ko’s team at Seoul National University of the Republic of Korea showed off the skin of active IR and camouflage on display, offering a cover platform required with a single entry variable during the day and night. Temperature (T). A soft thermoelectric device capable of cooling and heating functions as a backbone structure to adjust the surface area of each pixel, thus allowing thermal camouflage in the IR range, consistent with ambient temperature. Ko’s team extended the camouflage area to the IR-visible spectrum by inserting the thermochromic liquid crystal into the surface that changes the reflection (R) of light depending on the temperature of the device, controlling the temperature to indicate multiple colors. The camouflage system as a whole encompasses two independent spectra of the “full spectrum,” controlling temperatures with a single soft structure.
In addition to its ability to camouflage the device day and night, the device is highly “pixelated”. Thus, the camouflage skin can be mixed with sophisticated thermal and chromic background or camouflage when it is in transient motion from one background to another. Finally, the group showed real artificial camouflage skin in the human epidermis, on sophisticated backgrounds such as 1 bush or moving from one background to another, both in IR and in the spectacular spectrum.
Reference: Jinwoo Lee, Heayoun Sul, Yeongju Jung, Hyeonseok Kim, Seonggeun Han, Joonhwa Choi, Jaeho Shin, Dongkwan Kim, Jinwook Jung, Sukjoon Hong and Seung Hwan Ko, July 14, 2020, Advanced Functional Materials.
DOI: 10.1002 / adfm.202003328
Participating researchers: Jinwoo Lee (Seoul National University), Heayoun Sul (Seoul National University), Yeongju Jung (Seoul National University), Hyeonseok Kim (Seoul National University), Seonggeun Han (Seoul National University), Joonhwa Choi (Seoul University National), Jaeho Shin (Seoul National University), Dongkwan Kim (Seoul National University), Jinwook Jung (Seoul National University), Sukjoon Hong (Hanyang University) and Seung Hwan Ko (Seoul National University).
This work was supported by a grant from the National Research Foundation of Korea (NRF), funded through the Basic Science Research Program (2017R1A2B3005706).