Stretchable Capacitance Sensor against Strain Deformation

Abstract

Recently, stretchable electronics and sensor attracts increasing research interest with wearable and deformable electronics. For well combination with display applications capacitive based stretchable sensor is highly desired. However, the electrical stability of capacitance sensitivity between selection and non-selection states stretchable and the mechanical stability of capacitance are still challengeable. Poly(dimethylsiloxane)(PDMS) is widely used as the substrate material for stretchable electronics based on the beneficial merits of stable chemical properties, good thermal stability, transparency, and biological compatibility and its capability of attaining designer functionalities via surface modification and bulk property tailoring.[1] Metals that are liquid at or near room temperature are the only materials that have both metallic and fluidic properties.[2] Because they are liquid, they offer promising opportunities for electronics that are soft, flexible, stretchable, and even reconfigurable.[3] In this study, we approached to build stretchable capacitance sensor by multi-stacking combining of PDMS and liquid metals in specific laminated structure, which can preserve similar capacitance and stable capacitance selection sensitibity against of strain stress.In order to obtain stability of capacitance sensing against addressing stretching stress, multi-layered capacitance sensing electrodes structure of PDMS/Liquid Metal was designed, Fig 1(A). Also the sensor device was fabricated under low temperature curing condition of 80℃ where thermal stability condition of OLED Display is comparable. As a result, it was found that good stability of capacitance sensibility against addressing stress up to 20% strain stretching deformation. In this report, results of this study will be discussed in detail.