Strain Sensing Graphene Functionalized PET Films based on a Facile Dip Coating Approach

Strain sensing is crucial in emerging fields such as artificial/virtual reality applications, Internet-of-Things, and smart wearable devices. Strain sensors for the flexible applications are required to be reliable, structurally sound, and cost-effective for both small and vast fabrication batches. It is a challenging task to meet all the requirements yet reduced graphene oxide films show adequate coating on highly accessible substrates and provide proper figure of merits in terms of piezoresistive strain sensing. In this paper, high throughput single step coating of graphene oxide on flexible substrate and single step material functionalization method is presented for reduced graphene oxide based piezoresistive strain sensing on PET substrate. Physically patterned rGO/PET strain sensors are composed of 2 mm line width along a U-shaped 50 mm outline. Proposed rGO/PET film quality for sensor application was verified by Raman spectroscopy. Operation of the reduced graphene oxide based piezoresistive strain sensor is demonstrated to be repeatable via continuous cyclic bending tests.