Semi-liquid metal and adhesion-selection enabled rolling and transfer (SMART) printing: A general method towards fast fabrication of flexible electronics

Recent breakthrough in eutectic gallium-indium alloy has revealed its great potential in modern electronic engineering. Here, we established a general method towards super-fast fabrication of flexible electronics via semi-liquid metal and adhesion-selection enabled rolling and transfer (SMART) printing on various substrates. Based on the semi-liquid metal and its adhesion-difference on specifically designed target materials, we demonstrated that the rolling and transfer printing method could serve to rapidly manufacture a wide variety of complicated patterns with high resolution and large size. The process is much faster than most of the currently existing electronic fabrication strategies including liquid metal printing ever developed, and the cost either in time or consumption rate is rather low. As illustrated, a series of functional flexible and stretchable electronics such as multiple layer and large area circuits were fabricated to show their superior merit in combination with electrical conductivity and deformability. In addition, it was also demonstrated that the electronics fabricated in this way exhibited good repeatablity. A most noteworthy advantage is that all the fabrication processes could be highly automatic in the sense that user-friendly machines can thus be developed. This method paves a practical way for super-fast soft electronics manufacture and is expected to play an important role in the coming industry and consumer electronics.