Torsional Analysis and Measurement for Flexible Displays

Abstract

To display information, flexible displays are a promising device. We present energy methods in conjunction with the calculus of variation to obtain deflections of flexible substrates subject to torque. In addition to analytical derivation, in experiments an electric motor under computer control exerts torque to generate display torsion, whose twist angles are obtained by using both optical encoder measurement and theoretical calculation. Comparisons are made between experimental and theoretical results for PET (polyethylene terephthalate) and PEN (polyethylene naphthalate) polymer substrates. Both experimental and theoretical results show that the required torque due to unit twist angle increases with the twist angle. A larger PET substrate is not as easy to be twisted as smaller one. In addition, a square PET substrate is not as easy to be twisted as rectangular one with the same width.

Experimental and Simulated Investigations of Thin Polymer Substrates with an Indium Tin Oxide Coating under Fatigue Bending Loadings

“…Hamasha et al investigated the stability of an ITO film deposited on a PET substrate, subjecting it to strength, bending fatigue, thermal aging, and cycling [ 12 , 13 , 14 ]. Lee and Liu [ 15 , 16 ] developed theoretical solutions for flexible electronics under torsion loading.…”