Details

Autor(en) / Beteiligte

• Kwon, Yong‐Wook
• Lee, Jong‐Sung
• Joo, Young‐Chang
• Kim, Byoung‐Joon

Titel

In Twisting Motion, Stress‐Free Zone of Wearable Electronics

Ist Teil von

• Advanced electronic materials, 2020-03, Vol.6 (3), p.n/a

Erscheinungsjahr

2020

Quelle

Wiley Online Library Journals

Beschreibungen/Notizen

• Flexible electronics, such as flexible displays, batteries, and sensors, are under active development, and their mechanical reliability under repeated mechanical deformations is receiving a lot of attention. The mechanical stress under simple bending has been widely investigated, and the neutral plane located tensile and compressive region has been suggested for stress‐free zone under bending. However, to develop highly reliable twistable electronics, it is essential to elucidate the stress evolution during complex twisting deformation, and determine the stress‐free zone in twisting. The mechanical reliability of flexible indium tin oxide and Cu patterns during repeated twisting motions is reported. For fixed twisting, the patterns at the center show higher stability, but for free twisting, the patterns at the edge exhibit superior mechanical reliability. The mechanical stress evolution in twisting motion is analyzed by finite element method simulation, and the stress‐free zone according to twisting motion and base is proposed. Finally, the stress‐free zone is verified by conducting real twisting tests, such as the twisting motion of the human body. This study based on experimental reliability testing and computational simulation can provide guidelines to develop highly reliable twisting electronics. The stress‐free zone in the twisting of flexible electrode is investigated. Electrical resistances of ITO and Cu patterns on polymer substrate are measured during twisting, and mechanical stress is analyzed by using the FEM model. For the free twisting test, in which the sample length can be freely changed during the twisting test, the edge area exhibits infinite fatigue lifetime.