A fully integrated wearable electronic device with breathable and washable properties for long-term health monitoring

The fully integrated wearable electronics have recently found widespread applications in long-term health monitoring, where one major challenge is to develop substrate materials with excellent breathability and washability. In this work, we developed a fully integrated wearable electronic device with breathable and washable properties through a facile and scalable paradigm. We directly mixed hydrophilic graphene oxide with hydrophilic cellulose fibers to ensure that graphene nanosheets uniformly spread all over the paper matrix. Then laser reduction was applied to fabricate a graphene-cellulose temperature sensor (LRG-TS), and thermal reduction to make a graphene-cellulose pressure sensor (TRG-PS), both of which were then connected with a flexible printed circuit board (FPCB) to form a fully integrated wearable electronic device with results readable by a mobile phone through Bluetooth. The excellent breathability, attributed to the unique 3D hierarchical porous structure of the e-paper, lays a solid foundation for long-term monitoring as demonstrated in rabbit skin in vitro. Besides, it can endure long-term soaking in water and multiple washing-drying cycles without compromising structural integrity and functional performance, as shown by sensing of body temperature and human motion. The developed device with these two unparalleled properties holds great promise for versatile wearable electronics applications in personal healthcare monitoring.