Experimental investigation and modelling of flexible electrode-skin interface failure under combined cyclic loading and environmental effect
Abstract:
The novel technology of flexible electronics is based on flexible and deformable substrates. This technology has been drawing increasing attention from many fields such as information technology (smartphone, etc.), medical diagnostics (monitoring devices). Regardless of the significant stepping forward from laboratory to industry, flexible electronic devices are still facing enormous obstacles and challenges for the future. These obstacles and challenges are mostly related to the reliability and/or durability of the components under service conditions. As a matter of fact, the flexible electronic devices undergo in general flexural cyclic loading, which can give rise to the failure of the devices after a number of cycles. A better understanding of degradation mechanisms of relevant components is thus highly important for accurate lifetime prediction based on theoretical modelling and numerical analysis.

In the field of medical application, flexible sensors are increasingly used to monitor for example human body temperature and blood pressure. In this case, the sensors are often adhered to the skin through a sort of electrically conductive glue. In service, the flexible electrode-skin interface is subject to cyclic loading combined with environmental effect, which eventually leads to device signal instability or even failure of the monitoring system. This project aims to experimentally investigate the failure process of the flexible electrode-skin interface, and establish a model that can predict the service life of the flexible electrode. The goal is to develop a tool that integrates cyclic testing device, interface stress analysis, and electrical signal measurement, taking into account the service environmental conditions of the flexible sensor. The tool includes a variety of measurement and analysis capabilities such as measuring the evolution of the flexible electrode-skin interface integrity under different cyclic loading and humidity conditions, and modelling the interface damage evolution to predict the service life of the flexible electrode under different conditions. The results of this project will provide a theoretical reference for the reliability testing of flexible sensor systems.

Supervisor£ºDr  Zhidan SUN (Universite de Technologie de Troyes)
Dr Haibin ZHU (Institute of Flexible Electronics Technology of THU, Zhejiang)
Duration: 3 Years (at least 1.5 Years in IFET). IFET will provide a scholarship to cover the living costs during the PhD project (around 1200€ per month). The doctoral degree will be issued by the Universite de Technologie de Troyes.

Email: zhuhaibin@ifet-tsinghua.org ·µ»ØСľ³æ²é¿´¸ü¶à