Laser-engraved graphene for flexible and wearable electronics

Laser-engraved graphene (LEG) has been applied increasingly in flexible electronics over the past decade owing to its unique physical and chemical properties, and has shown great promise in energy controls, chemical and physical sensing, and telemedicine. In situ laser engraving has empowered graphene with additional versatilities such as miniaturized patterning, tunable composition, controllable morphology, and environmental friendliness. In this review, the technological advances of LEG from synthesis to applications in flexible and wearable electronic devices are summarized. Specifically, the use of LEG in designing next-generation nanogenerators, batteries, supercapacitors, physical sensors, gas sensors, biosensors, and wearable/telemedicine systems is discussed. An outlook related to LEG-based flexible electronics and key technological bottlenecks is identified.