Park, Haedong Kwon, Hyungho An, Yongsan Yu, Woong-Ryeol Moon, Myoung-Woon Hur, Kahyun 2024-01-19T23:00:42Z 2024-01-19T23:00:42Z 2021-09-03 2018-05 1862-6254 https://pubs.kist.re.kr/handle/201004/121424 There have been many studies on smart mechanical materials that sensibly deform in response to external stimuli. However, most of the previous studies have focused on structure changes but largely neglected stimuli-responsive and programmable mechanical properties. Here, we present a novel strategy of mechanical metamaterials, engineered materials with mechanical properties defined by their structure rather than their composition, to design smart materials that change their mechanical properties in response to external stimuli. The present work demonstrates mechanical metamaterials with thermoresponsive and reversible switching between positive and negative Poisson's ratios. In order to realize the thermoresponsive and reversible switching, a thermoresponsive rod with an extremely large thermal expansion coefficient is developed utilizing two-way shape memory effects. As an application of our metamaterials, we propose soundproofing materials that selectively block sound waves in a specific frequency range depending on temperature. English WILEY-V C H VERLAG GMBH SHAPE-MEMORY POLYMER THERMAL-EXPANSION Mechanical Metamaterials with Thermoresponsive Switching between Positive and Negative Poisson's Ratios Article 10.1002/pssr.201800040 1 PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS, v.12, no.5 PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS 12 5 scie scopus 000433591900008 2-s2.0-85042555011 Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Materials Science Physics Article SHAPE-MEMORY POLYMER THERMAL-EXPANSION high thermal expansion metamaterials negative thermal expansion Poisson&apos s ratio two-way shape memory effect