Precipitation-driven self-sintering for flexible electronics.

Flexible electronics (FE) require conductive materials that can be processed at low-temperature without compromising mechanical compliance. Here, we report a precipitation-driven self-sintering strategy that the highly conductive InGa3 film is formed on the flexible hydrogel under the ambient condition, and the solution-processable system is designed, where the liquid metal (LM) of InGa3 undergoes the controlled in situ precipitation and spontaneous microscale sintering process. The precipitation-driven self-sintering (PDSS) method uniquely enables the spontaneous and additive-free self-sintering of the metal microparticles (MPs) within the hydrogel matrices under the ambient condition, offering a scalable and substrate-friendly route for the FE. The pathway of InGa3 has the high conductivity, mechanical durability and adhesion to the flexible hydrogel without the high-temperature annealing, which is compatible with the scalable manufacturing method. These findings provide a versatile route toward the energy-efficient fabrication of the next-generation FE.