Self-Healing Thin-Film Transistor Circuits on Flexible Substrates

Thin-film transistor circuits on flexible substrates hold major promise for next-generation human-machine interface systems. However, a major bottleneck is the reliability of the interconnect, which is prone to open-circuit faults due to mechanical, electrical, and environmental stresses. Here, self-healing interconnects in thin-film transistor circuits are demonstrated on flexible substrates resulting in the restoration of >99% of the prefault current. The active material for self-healing is a dispersion of conductive particles in an insulating fluid that is contained over the interconnect. Healing is triggered by the electric field that appears in the open gap during the occurrence of the fault. The engineering of the active material is discussed; self-healing circuits are demonstrated and analyzed; and methods to package and integrate the self-healing feature are discussed with the process flow. This work sets a new benchmark for reliable inkjet-printed thin-film transistor circuits on flexible substrates.