A Liquid-Metal-Elastomer Nanocomposite for Stretchable Dielectric Materials
A Liquid-Metal-Elastomer Nanocomposite for Stretchable Dielectric Materials
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DOI：
10.1002/adma.201900663
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发表时间：
2019-06-01
影响因子：
29.4
通讯作者：
Majidi, Carmel
中科院分区：
文献类型：
--
作者：
Pan, Chengfeng;Markvicka, Eric J.;Majidi, Carmel
可拉伸的高介电常数材料对于可穿戴计算和软机器人等新兴领域的电子应用至关重要。虽然以前的工作显示了以介电纳米/微夹杂的形式嵌入在可拉伸基质中的有前途的材料结构，但这些材料有限的机械柔度大大限制了它们作为软能量收集/存储换能器和执行器的实际应用。在这里，提出了一类液态金属(LM)-弹性体纳米复合材料具有弹性和介电性能，使其独特地适合于应用于软物质工程。特别是，研究了液滴尺寸的作用，发现嵌入具有多分散分布的纳米级LM夹杂物的弹性体可以提高其电介电常数，而不会显著降低其弹性柔度、延伸性或介电击穿强度。相比之下，嵌入微滴的弹性体在介电常数方面表现出类似的改善，但击穿强度显著降低。通过增强介电弹性体致动器和能量收集换能器的性能，展示了用于软机械和电子产品的LM-弹性体纳米复合材料的独特使能特性和实用性。
Stretchable high-dielectric-constant materials are crucial for electronic applications in emerging domains such as wearable computing and soft robotics. While previous efforts have shown promising materials architectures in the form of dielectric nano-/microinclusions embedded in stretchable matrices, the limited mechanical compliance of these materials significantly limits their practical application as soft energy-harvesting/storage transducers and actuators. Here, a class of liquid metal (LM)-elastomer nanocomposites is presented with elastic and dielectric properties that make them uniquely suited for applications in soft-matter engineering. In particular, the role of droplet size is examined and it is found that embedding an elastomer with a polydisperse distribution of nanoscale LM inclusions can enhance its electrical permittivity without significantly degrading its elastic compliance, stretchability, or dielectric breakdown strength. In contrast, elastomers embedded with microscale droplets exhibit similar improvements in permittivity but a dramatic reduction in breakdown strength. The unique enabling properties and practicality of LM-elastomer nanocomposites for use in soft machines and electronics is demonstrated through enhancements in performance of a dielectric elastomer actuator and energy-harvesting transducer.