Fabrication of self-recoverable flexible and stretchable electronic devices

In this paper, we developed an EHD printing process for the fabrication of high-resolution self-recoverable flexible and stretchable electronics using low-melting-point metal inks. Three different metal inks were tested for their printability on four different substrates separately to demonstrate the capability of EHD printing technology. EHD printing enables low-cost direct fabrication of metallic conductors with sub-50 μm resolution, which represents a promising way to create electronic features with metallic conductivity and excellent flexibility and stretchability. When properly designed, the EHD printed electronics provided a stable resistance under hundreds of bending cycles and many stretching and releasing cycles with high tensile strain, which demonstrates their good flexibility and stretchability in electronics applications. The printed electronics was capable of self-healing under low temperature treatment to recover from failures without sacrificing its electrical properties. Moreover, a high-resolution capacitive sensor array was designed and fabricated. A Finite Element Analysis (FEA) model was developed to study the performance of the designed touch sensor. The results from FEA model agreed well with experimental results, which demonstrated the high-resolution capability of the EHD printing for the direction fabrication of flexible and stretchable devices.