Yu, Seunggun Cho, Hyesung Hong, Jun Pyo Park, Hyunchul Jolly, Jason Christopher Kang, Hong Suk Lee, Jin Hong Kim, Junsoo Lee, Seung Hwan Lee, Albert S. Hong, Soon Man Park, Cheolmin Yang, Shu Koo, Chong Min 2024-01-20T00:33:20Z 2024-01-20T00:33:20Z 2022-01-10 2017-09 2041-1723 https://pubs.kist.re.kr/handle/201004/122312 Designing topographic clusters is of significant interest, yet it remains challenging as they often lack mobility or deformability. Here we exploit the huge volumetric expansion (up to 3000%) of a new type of building block, thermally expandable microbombs. They consist of a viscoelastic polymeric shell and a volatile gas core, which, within structural confinement, create micro-clusters via inverse jamming and topographical close-packing. Upon heating, microbombs anchored in rigid confinement underwent balloon-like blowing up, allowing for dense clusters via soft interplay between viscoelastic shells. Importantly, the confinement is unyielding against the internal pressure of the microbombs, thereby enabling self-assembled clusters, which can be coupled with topographic inscription to introduce structural hierarchy on the clusters. Our strategy provides densely packed yet ultralight clusters with a variety of complex shapes, cleavages, curvatures, and hierarchy. In turn, these clusters will enrich our ability to explore the assemblies of the ever-increasing range of microparticle systems. English Nature Publishing Group Shaping micro-clusters via inverse jamming and topographic close-packing of microbombs Article 10.1038/s41467-017-00538-z 1 Nature Communications, v.8 Nature Communications 8 Y scie scopus 000411989800005 2-s2.0-85030086372 Multidisciplinary Sciences Science & Technology - Other Topics Article PHASE SUSPENSIONS BRICKS DNA jamming packing expandable bead EMI shielding