Investigation of LIG-based pressure sensors with various silicon-based elastomeric encapsulation layers

Laser-induced graphene (LIG) has attracted significant interest in the field of pressure sensors owing to the high sensitivity associated with its inherent three-dimensional porous structure. However, the brittleness of fabricated LIG poses a critical challenge in terms of durability. To address this issue, current research on LIG-based pressure sensors has focused on the utilization of Si-elastomer encapsulation layers. Despite the importance of the mechanical properties of Si elastomers for the performance of physical sensors, few studies have been conducted on the characterization of pressure sensors based on the encapsulation layer. In this study, we investigated the electromechanical characteristics of LIG-based pressure sensors encapsulated in various Si-based elastomers. For an unbiased evaluation, we first introduce a simple and reliable fabrication process for LIG-based pressure sensors with different Si-elastomer encapsulation layers. Subsequently, the electromechanical responses of the sensors were characterized using an automated pressure machine, demonstrating that sensors with encapsulation layers with a lower Young’s modulus exhibited increased resistance changes and extended response times. Finally, an in-depth exploration of the environmental stability of the pressure sensors was conducted for various encapsulation materials, ultimately confirming negligible performance variations based on the encapsulation materials.