Liquid metal encapsulated in Juncus effusus fiber via Zn2 +/Ga3+ dual-ion chelation as a TENG sensor for motion sensing

The expeditious development of Internet of Things (IoT) technology has led to a significant demand for wearable sensors. However, the unsustainable energy supply has restricted the development of wearable devices. Triboelectric nanogenerators (TENGs) have unique advantages such as simple preparation and high voltage output, making them a good solution to the energy problem of wearable devices. In this paper, the internal three-dimensional (3D) network structure of Juncus effusus (JE) fibers was utilized. By means of the coupling effect between sodium alginate (SA) and metal ions, the problem of the high surface tension of liquid metal (LM) was addressed. The LM was fixed within the internal network structure of the JE, and after encapsulation with Ecoflex, a flexible TENG sensor (LMSZE-JE) with self-powered sensing function was prepared. The LMSZE-JE sensor exhibits good voltage output performance, capable of outputting a peak voltage of 88.5 V at a frequency of 4 Hz, and maintaining good stability even after 6000 cycles. Weaving LMSZE-JE into a fabric can further increase the voltage output level, with a peak voltage of 135.6 V achievable at a frequency of 4 Hz. The high voltage output endows the LMSZE-JE sensor with good mechanical signal sensing capabilities. Fixing LMSZE-JE fibers and the fabric at human joints can effectively identify the movements of different joints. The JE based TENG sensor prepared in this paper has good voltage output performance and motion-sensing capabilities, providing a new strategy for the preparation of flexible LM based self-powered textile sensors.