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Abstract Liquid metal particle‐based microfibers attract great interest in soft and wearable electronics. The most facile method to fabricate sub‐50 µm liquid metal fiber is electrospinning. However, electrospinning has poor patterning ability and the electrospun fibers have inherent defects, which significantly lowers the electrical conductivity and limits their application. Therefore, better manufacturing methods are needed to precisely deposit high‐quality liquid metal fibers. In this work, an electrohydrodynamic printing process is developed to precisely pattern liquid metal microfibers with minimal defects and ultra‐high resolution (≈1.5 µm), overcoming the limitations of electrospinning. The patterned liquid metal fibers can be used for soft conductive composites and soft electronics with highly customized microscale features. The conductive composites embedded with these fibers not only exhibit high conductivity (up to 214 S cm−1), but also possess nearly strain‐insensitive resistance (7.3% resistance change at 200% strain) and exceptional cyclic stability. Additionally, the potential applications of the liquid metal fibers and composites in soft sensors, stretchable heaters, and transparent electrodes are demonstrated.
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Fabrication of Stretchable and Conductive Liquid Metal Microfibers through Coaxial Emulsion Electrospinning
Liquid metal fibers are increasingly used in soft multifunctional materials and soft electronics due to their superb stretchability, high conductivity, and lightweight. This work presents a systematic study of the electrospinning process of liquid metal microfibers. Compared to other methods that usually produce fibers thicker than 100 μm, electrospinning is a facile and low‐cost method of producing liquid metal fibers in the range of 10–100 μm. Specifically, core‐sheath liquid metal microfibers are fabricated with a highly conductive liquid metal core and a super‐stretchable thermoplastic elastomer sheath. This manufacturing process uses a liquid metal emulsion as the core solution, which circumvents manufacturing failures caused by the high surface tension of liquid metals. The influence of key processing parameters such as core flow rate, sheath flow rate, and applied voltage on the fiber diameter and morphology is studied by experiments. The mechanical and electrical properties of the as‐fabricated liquid metal microfibers, mats, and yarns are tested and discussed.
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- Award ID(s):
- 2143297
- PAR ID:
- 10588211
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Engineering Materials
- ISSN:
- 1438-1656
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.1002/adem.202402263
