Pan Chengfeng, Markvicka Eric J, Malakooti Mohammad H, Yan Jiajun, Hu Leiming, Matyjaszewski Krzysztof, Majidi Carmel
Integrated Soft Materials Lab, Carnegie Mellon University, Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
Integrated Soft Materials Lab, Carnegie Mellon University, Robotics Institute, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
Adv Mater. 2019 Jun;31(23):e1900663. doi: 10.1002/adma.201900663. Epub 2019 Apr 18.
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.
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。虽然先前的研究已经展示了以嵌入可拉伸基质中的介电纳米/微内含物形式存在的有前景的材料架构，但这些材料有限的机械柔顺性显著限制了它们作为软能量收集/存储换能器和致动器的实际应用。在此，提出了一类液态金属（LM）-弹性体纳米复合材料，其具有的弹性和介电性能使其特别适合软物质工程中的应用。特别地，研究了液滴尺寸的作用，发现嵌入具有纳米级LM内含物多分散分布的弹性体可以提高其介电常数，而不会显著降低其弹性柔顺性、拉伸性或介电击穿强度。相比之下，嵌入微米级液滴的弹性体在介电常数方面表现出类似的提高，但击穿强度显著降低。通过介电弹性体致动器和能量收集换能器性能的提升，证明了LM-弹性体纳米复合材料在软机器和电子设备中使用的独特性能和实用性。
