Direct mask printing of highly stretchable liquid metal electrodes for strain sensors

Flexible electronics, as an emerging technology, has shown potential applications in various fields. In recent years, gallium-based liquid metals have gained significant attention in the field of flexible electronics due to their exceptional metal conductivity and infinite ductility. However, achieving cost-effective and efficient patterning of liquid metal (LM) is crucial for the production of flexible electronic products. This article presents a novel liquid metal circuit printing technology that offers a rapid, affordable, and versatile solution to this challenge. Liquid metal patterned masks can be efficiently produced using laser cutting machines, eliminating the requirement for costly processing steps or equipment. Furthermore, direct mask printing enables the achievement of liquid metal circuit patterning. By employing this technique, a stretchable resistance strain sensor was successfully fabricated, exhibiting a remarkably extensive strain sensing range of 480% and commendable repeatability. These findings suggest that the aforementioned technology holds significant promise for the economical and expeditious realization of wearable health monitoring, intelligent sensing, and human-computer interaction.