We proposed flexible displays by using light-emitting liquid, electrochemiluminescent (ECL) solution. The ECL solution consisted of ruthenium complexes as ECL species and ionic liquid as nonvolatile solvent. We fabricated 50 × 50 pixels of ECL flexible displays. They emitted light during application of 50 Hz / 3.5 Vpp rectangular waves of voltage. The emitting area of one pixel was 200 × 200 μm2. The pixel pitch was 250 μm. The ECL solution was divided into each pixel by SU-8 partition and encapsulated by direct deposition of Parylene onto the liquid. The optical intensity of the displays did not decrease when they were bent along a convex curvature with a radius of 5 mm. In conclusion, highly flexible displays can be achieved by using ECL solution because liquid deforms repeatedly without mechanical destruction.
Ryo Okumura, Seiichi Takamatsu, Eiji Iwase, Kiyoshi Matsumoto, Isao Shimoyama, “Solution Electrochemiluminescent Microfluidic Cell for Flexible and Stretchable Display,” The 22nd IEEE International Conference on Micro Electro Mechanical Systems (MEMS '09), pp. 947-950, Sorrento, Italy, January 25-29, 2009. [Proceedings]