Conformal Theoretical Modeling of Arbitrary Shape Flexible Electronic Sensors Mounted onto General Curved Surface Substrate

Stretchable and flexible electronic sensors have been attracted due to their conformal integration onto complex curved surfaces for novel applications. Whereas, the mounting strains generated by the geometric mismatch of substrate surface and electronic sensors may cause non-conformal contact at the interface, thus would induce non-negligible effects on the performance of sensors. To figure out the influence rules of the shaped of electronic sensors and their geometric parameters on conformal contacts, this paper presents a novel conformal model to study the arbitrary shaped film as flexible sensors mounted onto general curved surface substrates. The principle of energy minimization and the method of integral summation play vital roles during the modeling, and three types of films with various shapes including rectangular, oval and hexagonal mounted onto bicurvature substrate are investigated. The influences of three dimensionless shape parameters of oval and hexagonal film/substrate contacts on dimensionless strain energy for conformal mounting are analyzed. The strain and critical dimensionless strain energy of three kinds of films/bicurvature substrate contacts are calculated and compared under the same conformal area. The results demonstrated that the contour shape of electronic sensor has a great effect on conformal mounting and strain. Thus, the developed conformal model would have great significance in guiding the design of flexible electronic devices and sensors when applied to general curved surface.