Shukla Darpan, Wang Hongyu, Awartani Omar, Dickey Michael D, Zhu Yong
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States.
Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States.
ACS Appl Mater Interfaces. 2024 Mar 20;16(11):14183-14197. doi: 10.1021/acsami.4c00318. Epub 2024 Mar 8.
Both liquid metal (LM) and metallic filler-based conductive composites are promising stretchable conductors. LM alloys exhibit intrinsically high deformability but present challenges for patterning on polymeric substrates due to high surface tension. On the other hand, conductive composites comprising metallic fillers undergo considerable decrease in electrical conductivity under mechanical deformation. To address the challenges, we present silver nanowire (AgNW)-LM-elastomer hybrid composite films, where AgNWs and LM are embedded below the surface of an elastomeric matrix, using two fabrication approaches, sequential and mixed. We investigate and understand the process-structure-property relationship of the AgNW-LM-elastomer hybrid composites fabricated using two approaches. Different weight ratios of AgNWs and LM particles provide tunable electrical conductivity. The hybrid composites show more stable electromechanical performance than the composites with AgNWs alone. In particular, 1:2.4 (AgNW:LMP w/w) sequential hybrid composite shows electromechanical stability similar to that of the LM-elastomer composite, with a resistance increase of 2.04% at 90% strain. The sequential approach is found to form AgIn intermetallic compounds which along with Ga-In bonds, imparts large deformability to the sequential hybrid composite as well as mechanical robustness against scratching, cutting, peeling, and wiping. To demonstrate the application of the hybrid composite for stretchable electronics, a laser patterned stretchable heater on textile and a stretchable circuit including a light-emitting diode are fabricated.
液态金属（LM）基和金属填料基导电复合材料都是很有前景的可拉伸导体。LM合金具有固有的高可变形性，但由于表面张力高，在聚合物基板上进行图案化存在挑战。另一方面，包含金属填料的导电复合材料在机械变形下电导率会大幅下降。为应对这些挑战，我们采用顺序法和混合法两种制备方法，制备了银纳米线（AgNW）-LM-弹性体混合复合薄膜，其中AgNW和LM嵌入在弹性体基质表面之下。我们研究并理解了用两种方法制备的AgNW-LM-弹性体混合复合材料的工艺-结构-性能关系。AgNW和LM颗粒的不同重量比可提供可调的电导率。与仅含AgNW的复合材料相比，混合复合材料表现出更稳定的机电性能。特别是，1:2.4（AgNW:LMP重量比）的顺序混合复合材料表现出与LM-弹性体复合材料相似的机电稳定性，在90%应变下电阻增加2.04%。发现顺序法形成了AgIn金属间化合物，其与Ga-In键一起，赋予顺序混合复合材料较大的可变形性以及抗刮擦、切割、剥离和擦拭的机械坚固性。为展示混合复合材料在可拉伸电子产品中的应用，制作了一种在纺织品上的激光图案化可拉伸加热器以及一个包括发光二极管的可拉伸电路。
