Double-layer liquid-surface printing of soft films for flexible electronics.

A double-layer liquid-surface printing method fabricates highly uniform, soft thin films by controlling spreading of 3D-printed polymer ink droplets on an immiscible liquid substrate.

• Why it matters: Uniform, defect-free soft thin films with minimal residual stress are difficult to produce and then transfer at high yield for flexible electronics.
• What they did: Polymer ink droplets are printed onto a double-layer immiscible liquid substrate to use liquid-surface smoothness and self-leveling for uniform spreading, then transferred onto curvilinear substrates.
• The result: The resulting films are defect-free and conformal, enabling patterned flexible electronics including flexible RFID tags deployed on curved food or packaging for real-time spoilage monitoring.