Stimuli-Responsive Structural Color Hydrogel Microbeads for Wearable Biometric Sensors

This paper describes stimuli-responsive structural color hydrogel microbeads as sensing elements for wearable biometric sensors. Since the structural color with a curved surface has no angle dependency, spherical shape of microbeads is suitable for partial uses of structural color-based eye-recognizable sensors. As a first step for demonstrating our concept, we fabricated temperature responsive structural color hydrogel microbeads and confirmed those structural color clearly changed by the temperature change. These microbeads could be encapsulated in a wearable flexible device and the biological information could be properly measured from different viewing angles. We believe this wearable sensor with structural color microbeads could become an effective approach for sensing the environment and healthcare targets.