Foldable and electrically stable graphene film resistors prepared by vacuum filtration for flexible electronics

• The conductive ink is modified by ionic cellulose ethers
• Foldable and electrically stable film resistors are fabricated with graphene conductive ink
• Ionic cellulose ethers have positive effect on the contact state of graphene layers

Flexible electronics have shown great application potential in mobile telemedicine, man-machine interaction system, and smart robotics. As a key electronic element, resistor's electrical properties should remain stable over their bending range of operation. Here, a shortcut fabrication strategy, vacuum filtration and cutting, to construct foldable and electrically stable graphene-based film resistors are demonstrated. Through investigation of resistor behavior under different stress conditions, it is found that micro-cracks appeared on the surface are correlated to curvature and percolation theories. The effects of ionic cellulose ethers on the contact state of graphene layers under tension and bending are investigated, which efficiently prevent surface crack from happening. This rapid fabrication method to carry out individual customization may further realize other environmental friendly, portable and multifunctional devices.