Embedded printing of graphene sponge sensors for sleep monitoring

Sleep disorders have emerged as a prevalent global issue, impacting physical and psychological health. Continuous and real-time sleep monitoring is crucial for improving sleep quality and preventing sleep-related health problems. This study presents an approach for developing sleep monitoring sensors by embedding three-dimensional graphene conductive network patterns (GCNP) onto sponges using the direct-write printing technique. The fabrication of GCNP sponge involves the precise assembly and patterning of graphene oxide (GO) onto a hydrophilic porous melamine sponge, ensuring an eco-friendly and customizable manufacturing process. This process allows the printed GO to infiltrate the sponge's inner structure, forming a strong, three-dimensional interconnected conductive network via hydrogen bonding and self-assembly. The resulting GCNP sponge exhibits satisfactory softness (Modulus = 36.2 kPa), sensitivity (206.85 kPa⁻¹) and excellent stability (withstand 2500 compression cycles). The pressure sensors utilizing GCNP sponges have the capability to monitor sleep posture and breathing behavior, offering potential for enhancing sleep quality and addressing sleep-related disorders. This work demonstrates a promising and cost-effective method for developing comfortable, sensitive, and stable sleep monitoring sensors.