Abstract
With high flexibility, stretchability, and conformality, flexible electronic products realize the natural interaction between electronic devices and the human body; moreover, they facilitate applications such as wearable devices. The core of any flexible electronic device typically comprises of a flexible substrate, an active conductive layer, and an interface layer. In this study, polyimide is the primary flexible polymeric substrate of the device, and the active layer comprises of 10 alternating layers of 20-nm-thick Ni and 20-nm-thick Nb nanolaminates. Furthermore, a monometal nanolaminate stack of Ni by repeated deposition of 20-nm-thick Ni layers twenty times was fabricated as a control sample. A customized rate-dependent bending failure/fracture test system was used to analyze the conductance profile of the sample. The resistance change of the device was obtained as a function of the loading cycle to analyze the device performance under repeated loading cycles. Nanoindentation experiments were also conducted to obtain the hardness and Young’s modulus of the sample before and after the reliability test and examine the evolution of the mechanical property changes with cyclic loading.