At this year’s SID/DSCC Business Conference at Display Week, KAIST Professor Beyong-Soo Bae gave a comprehensive presentation on the science of the bend in flexible displays. Dr. Bae highlighted the different types of foldable techniques, including variations on in-folding, out-folding, multiple sliding, and rolling. His presentation covered the benefits and challenges of each and then went into the math behind creating a metric for bending stiffness to create what KAIST calls 1/Flexibility.
This is defined in the image below and follows the primary axiom that a thinner film and module will yield reduced elongation and bending stiffness.
Key issues to consider during folding include inside compression and outside tension,
elongation, and restoring force leading to bending stiffness in select folding modalities (out-folding vs. in-folding, for example).
KAIST needed to consider where the fold in the display occurs, the distance from the neutral plane, and the radius of the curvature of the display. Dr. Bae said that this work was augmented by prior work done by IMID.
To deal with the unique material science challenges bendable displays impose, KAIST created a spin-off company, Solip Technologies, now headed by Dr. Bae. His presentation highlighted the company’s focus on bendable display solutions to help get us to bendable display nirvana. -- Stephen Sechrist