Highly Stable Indium-Gallium-Zinc-Oxide Thin-Film Transistors on Deformable Softening Polymer Substrates

Flexible electronics are attracting great interest in healthcare, where devices such as thin-film transistors (TFTs) on polymer substrates facilitate biomedical applications requiring complex circuits in soft packages. Consequently, a repeatable process to fabricate reliable, stable electronic components on flexible substrates is required. Here, thermoset thiol-ene/acrylate shape memory polymer (SMP) substrates house indium-gallium-zinc-oxide (IGZO) TFTs and logic circuits: resulting devices exhibit stable behavior after thermal annealing at 250 degrees C. Fabricated, annealed devices exhibit an average mobility of 15 +/- 2.5 cm(2) V-1 s(-1) and show stability after bending and soaking in aqueous media. TFTs on SMPs are studied after mechanical bending tests with radii of curvature of 5 mm for 10(4) cycles over a 4 h time period. Other TFTs are soaked in phosphate-buffered saline solution at 37 degrees C for 1 week. Logic inverter circuits using IGZO TFTs on SMPs represent the ability to add complex circuitry onto thin film flexible electronics. This technology can enable a new generation of implantable devices for research in healthcare fields.