A novel graphene-based inkjet-printed WISP-enabled wireless gas sensor

In this paper we demonstrate the design and development of a low-cost, self-powered, wireless sensor solution based on the WISP platform and utilizing thin films produced from environmentally friendly, water-based, inkjet printed graphene oxide (GO) ink. The sensor demonstrates good response to ammonia gas (NH₃), yielding a 6% normalized resistance change within 15 minutes after exposure to a concentration of 500 ppm. In addition, excellent recovery time is achieved using the graphene thin films, with over 30% of material recovery observed within 5 minutes without exposure to high temperature or any UV treatments. In addition to reporting the first ever integration of inkjet-printed water soluble GO inks into low cost RF electronics fabricated on flexible substrates, we also bring gas sensing capabilities to RFID tags relying on purely wireless digital transmission of the sensed information. The introduction of mass producible, stable, environmentally friendly, inkjet printable GO on organic paper/Kapton substrates lays the foundation for the development of a wide range of new low-cost, high performance graphene-based devices, such as inkjet-printed diodes, capacitors and transistors.