School of Industrial Engineering, Purdue University, West Lafayette, IN, 47907, USA.
Birck Nanotechnology Center, Purdue University, West Lafayette, IN, 47907, USA.
Adv Mater. 2019 Apr;31(14):e1807811. doi: 10.1002/adma.201807811. Epub 2019 Feb 13.
In this work, a general mechanism is discovered to form liquid-metal-based, stable and stretchable conductive patterns on rigid and soft substrates. It is discovered that pulsed laser irradiation of liquid metal nanoparticles (LMNPs) with tunable conditions can induce transformation to stable and stretchable solid-liquid (S-L) dual phases on various surfaces. Formation of this unique solid-liquid composite phase is the key to change the wetting behavior of the conductive patterns on various substrates and enables mechanically stable patterns on various substrates. Pulsed-laser-driven thermo-mechanical shock momentum is important for rupture and joining of the LMNPs, providing much better control than the traditional mechanical sintering. The solid nanophase forms a nanoporous matrix filled with and wetted by the LM, thereby providing a stabilization mechanism for the S-L composite patterned thin film. The mechanical and thermal reliability of the solid-liquid patterns is investigated. The S-L patterns can stretch up to 30% strain and cycle stably for 7000 cycles. It can be heated up to 177 °C with an input power of 0.58 W. The solid-liquid composite film provides great opportunity for various applications as a flexible conductor with unique mechanical and physics properties and further inspires design of LM devices for completely exposed applications.
在这项工作中，发现了一种在刚性和柔性基底上形成基于液态金属的、稳定且可拉伸的导电图案的通用机制。发现通过可调条件的脉冲激光辐照液态金属纳米颗粒（LMNP）可以在各种表面上诱导稳定且可拉伸的固-液（S-L）双相的转变。这种独特的固-液复合相的形成是改变各种基底上导电图案润湿性并使各种基底上具有机械稳定图案的关键。脉冲激光驱动的热机械冲击动量对于 LMNPs 的破裂和结合很重要，提供了比传统机械烧结更好的控制。固体纳米相形成纳米多孔基质，填充有和被 LM 润湿，从而为 S-L 复合图案薄膜提供了稳定化机制。对固-液图案的机械和热可靠性进行了研究。S-L 图案可拉伸至 30%的应变并稳定循环 7000 次。它可以在 0.58 W 的输入功率下加热至 177°C。固-液复合薄膜为具有独特机械和物理性能的柔性导体提供了极好的应用机会，并进一步激发了完全暴露应用的 LM 器件的设计。
