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This content will become publicly available on April 17, 2023

Title: On‐Demand Programming of Liquid Metal‐Composite Microstructures through Direct Ink Write 3D Printing
Soft, elastically deformable composites with liquid metal (LM) droplets can enable new generations of soft electronics, robotics, and reconfigurable structures. However, techniques to control local composite microstructure, which ultimately governs material properties and performance, is lacking. Here a direct ink writing technique is developed to program the LM microstructure (i.e., shape, orientation, and connectivity) on demand throughout elastomer composites. In contrast to inks with rigid particles that have fixed shape and size, it is shown that emulsion inks with LM fillers enable in situ control of microstructure. This enables filaments, films, and 3D structures with unique LM microstructures that are generated on demand and locked in during printing. This includes smooth and discrete transitions from spherical to needle-like droplets, curvilinear microstructures, geometrically complex embedded inclusion patterns, and connected LM networks. The printed materials are soft (modulus < 200 kPa), highly deformable (>600 % strain), and can be made locally insulating or electrically conductive using a single ink by controlling the process conditions. These capabilities are demonstrated by embedding elongated LM droplets in a soft heat sink, which rapidly dissipates heat from high-power LEDs. These programmable microstructures can enable new composite paradigms for emerging technologies that demand mechanical compliance with multifunctional more » response. « less
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Award ID(s):
2054409 2054411
Publication Date:
Journal Name:
Advanced Materials
Page Range or eLocation-ID:
Sponsoring Org:
National Science Foundation
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