State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096, China.
Biosensors (Basel). 2022 Dec 26;13(1):28. doi: 10.3390/bios13010028.
Conductive and stretchable fibers are the cornerstone of intelligent textiles and imperceptible electronics. Among existing fiber conductors, gallium-based liquid metals (LMs) featuring high conductivity, fluidity, and self-healing are excellent candidates for highly stretchable fibers with sensing, actuation, power generation, and interconnection functionalities. However, current LM fibers fabricated by direct injection or surface coating have a limitation in shape programmability. This hinders their applications in functional fibers with tunable electromechanical response and miniaturization. Here, we reported a simple and efficient method to create shape-programmable LM fibers using the phase transition of gallium. Gallium metal wires in the solid state can be easily shaped into a 3D helical structure, and the structure can be preserved after coating the wire with polyurethane and liquifying the metal. The 3D helical LM fiber offered enhanced stretchability with a high breaking strain of 1273% and showed invariable conductance over 283% strain. Moreover, we can reduce the fiber diameter by stretching the fiber during the solidification of polyurethane. We also demonstrated applications of the programmed fibers in self-powered strain sensing, heart rate monitoring, airflow, and humidity sensing. This work provided simple and facile ways toward functional LM fibers, which may facilitate the broad applications of LM fibers in e-skins, wearable computation, soft robots, and smart fabrics.
导电线和可拉伸纤维是智能纺织品和隐形电子产品的基石。在现有的纤维导体中，具有高导电性、流动性和自修复性的镓基液态金属 (LM) 是具有传感、致动、发电和互联功能的高可拉伸纤维的优秀候选材料。然而，目前通过直接注入或表面涂层制造的 LM 纤维在形状可编程性方面存在局限性。这限制了它们在具有可调机电响应和小型化的功能纤维中的应用。在这里，我们报告了一种使用镓的相变来制造形状可编程 LM 纤维的简单而有效的方法。固态下的镓金属线可以很容易地形成 3D 螺旋结构，并且在涂覆聚氨酯并使金属液化后，该结构可以保留下来。3D 螺旋 LM 纤维具有增强的拉伸性，断裂应变高达 1273%，在 283%的应变下表现出不变的电导率。此外，我们可以通过在聚氨酯固化过程中拉伸纤维来减小纤维直径。我们还展示了编程纤维在自供电应变传感、心率监测、气流和湿度感应方面的应用。这项工作为功能性 LM 纤维提供了简单易行的方法，这可能有助于 LM 纤维在电子皮肤、可穿戴计算、软机器人和智能织物中的广泛应用。
