A crew at Pohang College of Science and Expertise (POSTECH), spearheaded by Professor Su Seok Choi and Ph.D. candidate Seungmin Nam from the Division of Electrical Engineering, has developed a novel stretchable photonic gadget that may management mild wavelengths in all instructions. This pioneering examine was revealed in Mild: Science & Purposes on Might 22.
Structural colours are produced via the interplay of sunshine with microscopic nanostructures, creating vibrant hues with out counting on conventional shade mixing strategies. Standard shows and picture sensors mix the three major colours (purple, inexperienced, and blue), whereas structural shade know-how leverages the inherent wavelengths of sunshine, leading to extra vivid and numerous shade shows. This progressive method is gaining recognition as a promising know-how within the nano-optics and photonics industries.
Conventional shade mixing methods, which use dyes or luminescent supplies, are restricted to passive and stuck shade illustration. In distinction, tunable shade know-how dynamically controls nanostructures akin to particular mild wavelengths, permitting for the free adjustment of pure colours. Earlier analysis has primarily been restricted to unidirectional shade tuning, sometimes shifting colours from purple to blue. Reversing this shift — from blue to purple, which has an extended wavelength — has been a big problem. Present know-how solely permits changes in direction of shorter wavelengths, making it tough to realize numerous shade illustration within the supreme free wavelength course. Due to this fact, a brand new optical gadget able to bidirectional and omnidirectional wavelength adjustment is required to maximise the utilization of wavelength management know-how.
Professor Choi’s crew addressed these challenges by integrating chiral liquid crystal elastomers (CLCEs) with dielectric elastomer actuators (DEAs). CLCEs are versatile supplies able to structural shade modifications, whereas DEAs induce versatile deformation of dielectrics in response to electrical stimuli. The crew optimized the actuator construction to permit each growth and contraction, combining it with CLCEs, and developed a extremely adaptable stretchable gadget. This gadget can freely regulate the wavelength place throughout the seen spectrum, from shorter to longer wavelengths and vice versa.
Of their experiments, the researchers demonstrated that their CLCE-based photonic gadget may management structural colours over a broad vary of seen wavelengths (from blue at 450nm to purple at 650nm) utilizing electrical stimuli. This represents a big development over earlier applied sciences, which had been restricted to unidirectional wavelength tuning.
This analysis not solely establishes a foundational know-how for superior photonic units but in addition highlights its potential for varied industrial functions.
Professor Choi remarked, “This know-how might be utilized in shows, optical sensors, optical camouflage, direct optical analogue encryption, biomimetic sensors, and sensible wearable units, amongst many different functions involving mild, shade, and additional broadband electromagnetic waves past seen band. We goal to increase its utility scope via ongoing analysis.”
