CNT-assisted design of stable liquid metal droplets for flexible multifunctional composites

Gallium-based liquid metals (LMs) hold great promise as potential star materials for wearable and flexible electronics due to their superior electrical conductivity, high thermal conductivity, and good deformability. However, it remains still a huge challenge to realize the good dispersion of LM droplets. Herein, we demonstrated the design of highly stable LM droplets with the assistance of carbon nanotubes (CNTs). The resultant CNT@LM droplets showed excellent dispersion stability, without obvious precipitation even after settling for 30 days. The CNT@LM droplets could be easily sprayed onto diverse polymer substrates (thermoplastic polyurethanes, cellulose, and polyethylene terephthalate), showing an electrical conductivity of 1.0 x 106 S/m and a superior electromagnetic interference shielding effectiveness of 50.9 dB at only 5 mu m thickness. Moreover, the CNT@LM droplets exhibited a homogeneous dispersion in waterborne polyurethane and it was demonstrated the asprepared composite films excellent Joule heating performance with a high saturation temperature (63.0. C) at a low supplied voltage (2.0 V). In addition, a superior out-plane thermal conductivity of 2.19 W/(m center dot K) was achieved for the composite films. This work provides a novel idea to address the agglomeration of LMs, opening a promising avenue for their practical applications in wearable and flexible electronics.

Automated summary

This study demonstrates the design of highly stable liquid metal droplets assisted by carbon nanotubes, which can easily disperse on various polymer substrates and exhibit excellent electrical conductivity and electromagnetic interference shielding effectiveness. The resulting composite films also show outstanding Joule heating performance and thermal conductivity.