Researchers develop film-like soft robot actuator capable of detecting methanol in water

By Park Sae-jin Posted : February 15, 2023, 13:54 Updated : February 15, 2023, 14:16

[Courtesy of KIST]

SEOUL -- Researchers from a prominent state research institute have developed a film-like soft robot composed of chiroptical photonic crystals, which are optical nanostructures, that can detect methanol (CH3OH) in water. The robot can also fold, bend, and twist in response to external stimuli.
Chiroptic is a term referring to the optical technique that uses refraction, absorption, or emission of anisotropic radiation for investigating chiral substances including methanol (CH3OH), 2-butanol (CH3CHCH2CH3), and all types of amino acids except glycine. Chiroptical sensors can detect alcohols and other chiral substances in the air or in a solution.
Methanol is a water-soluble and flammable liquid with a distinctive alcoholic odor similar to that of ethanol. The substance is extremely poisonous and can cause blindness or severe organ failure that could lead to death when only a small amount of up to 240 milliliters is consumed. Methanol is widely used as the core material for the production of everyday products such as plastics, paints, and construction materials.
The Korea Institute of Science and Technology (KIST) said that its research team led by Professor Kim Dae-yoon developed a photonic crystal soft robot capable of detecting methanol in water. Photonic crystals were used to reflect the light of specific wavelengths when the film-shaped robot is stimulated by its surrounding environment.
The robot was constructed in an asymmetric "Janus" structure with its outer active optical layer made of cholesteric liquid crystal polymer and an inner structure composed of polymeric thin gel film. The film-shaped robot can morph from a two-dimensional shape into a three-dimensional shape and mimic the movements of other animals like a caterpillar crawling or an ant lifting up a leaf.
Most robots are composed of electrical wires and circuit boards located inside a hard, protective casing. Such types of robots can withstand external force and perform tasks such as lifting up a heavy object or carrying bulky items but they cannot fit into a tiny space or perform complicated tasks in cramped areas. Meanwhile, soft robots with film-like skin or no protective layer can change their shape and perform tasks in small spaces.
"The film-like robot was developed as a kit package type that can be intuitively used by anyone. It also does not need external electricity for operation. Its helical shape also makes other companies create rip-off products," KIST researcher Kim Dae-yoon said in a statement on February 15.
기사 이미지 확대 보기