Flexible conductive fibers have attracted much attention in the field of flexible electronics. The research focus of this field is to manufacture a multifunctional conductive fiber that can deform rapidly and has a large tensile range. In recent years, the flexible Device research group led by Associate Professor Sheng Bin of Academician Zhuang Songlin Ultra-precision Optical Manufacturing Team of University of Shanghai for Science and Technology focuses on the fabrication and application of flexible optical/electrical components, and has achieved a series of research achievements. The research was recently published as the cover paper in Soft Matter, and was highlighted by the Royal Society of Chemistry (RSC). Xiong Yan, the 2019 graduate student, is the first author, and Associate Professor Sheng Bin is the corresponding author.
In this study, a new method was proposed to produce electrothermal deformable conductive fiber (DCF) by injecting liquid metal into hollow thermoplastic polyurethane (TPU) fiber. DCF can be molded into any 2D or 3D shape above the thermoplastic temperature point of TPU by electrothermal method. Combined with the solid-liquid phase transformation characteristics of liquid metal at its melting point, DCF shows special shape memory characteristics at the two phase transition points. The double torsional DCF and spiral DCF can be used as capacitive sensor and inductor sensor for human motion monitoring respectively. In addition, the spiral DCF can also be used as a stretchable electrode, and the resistance change is less than 0.2% under the condition of the maximum mechanical strain of 3300%, which has good flexible electrical performance. In conclusion, the electrothermal deformable conductive fiber has great application potential in human motion monitoring, soft ware and intelligent electronic fabric.
Figure 1: Working principle and sample of electrothermal deformable conductive fiber
Figure 2： Cover of Soft Matter