Jung Dongjun, Lim Chaehong, Park Chansul, Kim Yeongjun, Kim Minseong, Lee Seunghwan, Lee Hyunjin, Kim Jeong Hyun, Hyeon Taeghwan, Kim Dae-Hyeong
Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul, 08826, Republic of Korea.
School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul, 08826, Republic of Korea.
Adv Mater. 2022 Jun;34(23):e2200980. doi: 10.1002/adma.202200980. Epub 2022 May 6.
Highly conductive and stretchable nanocomposites are promising material candidates for skin electronics. However, the resistance of stretchable metallic nanocomposites highly depends on external strains, often deteriorating the performance of fabricated electronic devices. Here, a material strategy for the highly conductive and stretchable nanocomposites comprising metal nanomaterials of various dimensions and a viscoelastic block-copolymer matrix is presented. The resistance of the nanocomposites can be well retained under skin deformations (<50% strain). It is demonstrated that silver nanomaterials can self-organize inside the viscoelastic media in response to external strain when their surface is conjugated with 1-decanethiol. Distinct self-organization behaviors associated with nanomaterial dimensions and strain conditions are found. Adopting the optimum composition of 0D/1D/2D silver nanomaterials can render the resistance of the nanocomposites insensitive to uniaxial or biaxial strains. As a result, the resistance can be maintained with a variance of < 1% during 1000 stretching cycles under uniaxial and biaxial strains of <50% while a high conductivity of ≈31 000 S cm is achieved.
高导电性和可拉伸的纳米复合材料是皮肤电子学领域很有前景的候选材料。然而，可拉伸金属纳米复合材料的电阻高度依赖于外部应变，这常常会降低所制造电子设备的性能。在此，我们提出了一种用于高导电性和可拉伸纳米复合材料的材料策略，该复合材料由各种尺寸的金属纳米材料和粘弹性嵌段共聚物基体组成。在皮肤变形（应变<50%）下，纳米复合材料的电阻能够得到很好的保持。结果表明，当银纳米材料的表面与1-癸硫醇共轭时，它们能够在粘弹性介质中响应外部应变而自组装。我们发现了与纳米材料尺寸和应变条件相关的不同自组装行为。采用0D/1D/2D银纳米材料的最佳组成可以使纳米复合材料的电阻对单轴或双轴应变不敏感。因此，在<500%的单轴和双轴应变下进行1000次拉伸循环时，电阻变化<1%，同时可实现约31000 S/cm的高电导率。
