Solution Electrochemiluminescent Microfluidic Cell for Flexible and Stretchable Display

We developed liquid luminescent flexible displays using electrochemiluminescent solution as deformable luminescent material. The solution consisted of ruthenium complexes as light emitting material and ionic liquid as nonvolatile solvent. We injected the solution, to pattern and seal it, into microfluidic cells between two flexible films of polyethylene terephthalate substrates with indium tin oxide electrodes. The light emitting area of one cell was 2times2 mm². The gap between the electrodes was 100 mum. We measured the luminance of the cell during application of 50 Hz/4.0 Vpp (peak-to-peak value) rectangular waves of voltage in bent condition. The device was bent along the convex curvature with radii of 60, 30 and 20 mm. The luminance was reduced by only 30 % when the radius of cells are suitable for flexible displays because they can tolerate large deformation of bending.