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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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This content will become publicly available on July 25, 2026
Toward Standardized Microscale Tensile Testing for Two‐Photon Polymerization‐Fabricated Materials in Liquid
Two‐photon polymerization (TPP) enables the fabrication of intricate 3D microstructures with submicron precision, offering significant potential in biomedical applications like tissue engineering. In such applications, to print materials and structures with defined mechanics, it is crucial to understand how TPP printing parameters impact the material properties in a physiologically relevant liquid environment. Herein, an experimental approach utilizing microscale tensile testing (μTT) for the systematic measurement of TPP‐fabricated microfibers submerged in liquid as a function of printing parameters is introduced. Using a diurethane dimethacrylate‐based resin, the influence of printing parameters on microfiber geometry is first explored, demonstrating cross‐sectional areas ranging from 1 to 36 μm2. Tensile testing reveals Young's moduli between 0.5 and 1.5 GPa and yield strengths from 10 to 60 MPa. The experimental data show an excellent fit with the Ogden hyperelastic polymer model, which enables a detailed analysis of how variations in writing speed, laser power, and printing path influence the mechanical properties of TPP microfibers. The μTT method is also showcased for evaluating multiple commercial resins and for performing cyclic loading experiments. Collectively, this study builds a foundation toward a standardized microscale tensile testing framework to characterize the mechanical properties of TPP printed structures.
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- Award ID(s):
- 2503605
- PAR ID:
- 10634098
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Small Science
- ISSN:
- 2688-4046
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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