{"id":32,"date":"2020-10-13T10:51:45","date_gmt":"2020-10-13T02:51:45","guid":{"rendered":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/?page_id=32"},"modified":"2025-11-29T11:12:25","modified_gmt":"2025-11-29T03:12:25","slug":"research","status":"publish","type":"page","link":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/research\/","title":{"rendered":"Research"},"content":{"rendered":"<p><span style=\"color: #3366ff\">Mechanical metamaterials <\/span>are artificially structured materials designed to exhibit properties not found in naturally occurring materials, such as negative Poisson\u2019s ratio, negative thermal expansion, negative stiffness, negative mass density, and programmable properties. These properties are typically achieved by engineering the material&#8217;s internal structure at a micro or nanoscale, rather than by altering its chemical composition. We design (active) mechanical metamaterials and establish a general physical theory of these designed structures.<\/p>\n<h3 style=\"font-weight: 400;text-align: center\"><span style=\"color: #0000ff;background-color: #99ccff\">i. Fundamental Research (Engineering Mechanics)<\/span><\/h3>\n<h4><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone size-full wp-image-37\" src=\"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230105819_91616-1.png\" width=\"1280\" height=\"720\" srcset=\"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230105819_91616-1.png 1280w, https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230105819_91616-1-300x169.png 300w, https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230105819_91616-1-1024x576.png 1024w, https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230105819_91616-1-768x432.png 768w\" sizes=\"(max-width: 1280px) 100vw, 1280px\" \/><\/h4>\n<p><span style=\"color: #3366ff\">Meta-statics:<\/span> We identify and quantify mechanical couplings of 2D and 3D lattice structures using nonclassical continuum models and crystallographic symmetry theories. We also explore the design of metamaterials with nonreciprocal constitutive equations.<\/p>\n<p><span style=\"color: #ff0000\"><em>Keywords: mechanical coupling, micropolar theory, crystallographic theories, symmetry breaking, nonreciprocal behavior<\/em><\/span><\/p>\n<p><span style=\"color: #3366ff\">Meta-dynamics:<\/span> We design metastructures for vibration isolation by integrating kinematic mechanisms with lattice mechanics. By leveraging instability, we create metamaterials with quasi-zero stiffness (QZS) to isolate vibrational motion for multi-modal and selective frequency ranges.<\/p>\n<p><span style=\"color: #ff0000\"><em>Keywords: vibration isolation, quasi-zero stiffness, mechano-intelligence<\/em><\/span><\/p>\n<p><span style=\"color: #3366ff\">Meta-design:<\/span> We develop active mechanical metamaterials and devices such as mechanical computers and robotic metamaterials. We design lattice geometries using smart materials like shape-memory polymers, shape-memory alloys, piezoelectric materials, magnetic materials, and liquid metals, and manufacture devices using 3D\/4D printing techniques.<\/p>\n<p><span style=\"color: #ff0000\"><em>Keywords: active lattice structures, multi-physics, instability, heat transfer, mechanical computing, robotic metamaterials, physical intelligence<\/em><\/span><\/p>\n<p style=\"text-align: center\"><span style=\"color: #0000ff;background-color: #99ccff\">ii. Applied Research (Mechanical Engineering)<\/span><\/p>\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" class=\"alignnone size-full wp-image-38\" src=\"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230110417_53077-1.png\" alt=\"\" width=\"1280\" height=\"718\" srcset=\"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230110417_53077-1.png 1280w, https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230110417_53077-1-300x168.png 300w, https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230110417_53077-1-1024x574.png 1024w, https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-content\/uploads\/sites\/9\/2020\/10\/20181230110417_53077-1-768x431.png 768w\" sizes=\"(max-width: 1280px) 100vw, 1280px\" \/><\/figure>\n\n\n<p><span style=\"color: #3366ff\">Meta-wheels:<\/span> Metamaterials can be used to design spokes and shear bands of airless wheels using the theories of elasticity and nonlinear solid mechanics. The principles from meta-statics and meta-dynamics are applied in this endeavor.<\/p>\n<p><span style=\"color: #ff0000\"><em><span style=\"font-size: 1.33333rem;font-weight: inherit\">Keywords: ring mechanics, visco-hyperelastic elastomer composites, nonreciprocal mechanics, optimization<\/span><\/em><\/span><\/p>\n<p>&nbsp;<\/p>\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Mechanical metamaterials are artificially structured materials designed to exhibit properties not found in naturally occurring materials, such as negative Poisson\u2019s ratio, negative thermal expansion, negative stiffness, negative mass density, and programmable properties. These properties are typically achieved by engineering the material&#8217;s internal structure at a micro or nanoscale, rather than by altering its chemical composition. [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"disabled","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-32","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/pages\/32","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/comments?post=32"}],"version-history":[{"count":11,"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/pages\/32\/revisions"}],"predecessor-version":[{"id":585,"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/pages\/32\/revisions\/585"}],"wp:attachment":[{"href":"https:\/\/sites.gc.sjtu.edu.cn\/jaehyungju\/wp-json\/wp\/v2\/media?parent=32"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}