A flexible electrode with tetra-chiral structure connected in serpentine shape

Flexible electrodes are usually well-matched to the substrate as the core component of flexible electronics technology. However, when large deformation occurs, the conductive layer of flexible electrodes can mechanically fracture due to insufficient mechanical properties, leading to the failure of flexible electronic devices. Improving the mechanical properties of flexible electrodes is essential for the development of flexible electronics. Herein, a flexible electrode with a serpentine shape tetra-chiral structure is designed and fabricated via screen-printed process based on existing tetra-chiral structure. The research demonstrates that the serpentine tetra-chiral structure can improve the mechanical properties of the flexible electrode and the maximum tensile stress is reduced by 87.19% relative to existing tetra-chiral structure. The flexible electrode is still conductive when the strain of that is 70%, and the resistance is only 5Ω and 4.4Ω, respectively, at a bending angle of 180° and following 1,000 times fold cycles. In addition, the flexible electrodes fabricated in this paper are utilized to realize the collection of ECG signals and pulse signals, showing greater potential in biological signal monitoring. The strategy proposed here is expected to maintain electrodes’ original functions under repeated use and complex deformation.