Gao Chao's team creatively proposed a material preparation method of "large-scale micro-wrinkles": first, large sheets of single-layer graphene are overlapped with each other. After high-temperature heat treatment, the oxygen-containing groups in the material release gas, forming micro-air pockets inside the material. Finally, The temperature is lowered and mechanically rolled to form a film, so that the gas in the airbag is discharged to form micro-wrinkles.

 

Under the action of external force, the micro-wrinkles on the graphene film will produce elastic deformation. The greater the external force, the more obvious the deformation will be. Experimental data shows that compared with traditional graphite membrane materials, the elongation at break of graphene membranes is increased by 2 to 3 times.

 

According to the researchers, the ductility of graphene microfolds allows it to withstand various complex deformations such as repeated folding, knotting, twisting, bending, origami, and is also more suitable for industrial-scale production.

 

The highly flexible graphene film also has excellent thermal and electrical conductivity. In fact, the thermal conductivity of graphene films exceeds the thermal conductivity of macroscopic materials currently on the market, with an average of 1900 W/m·degree.

 

According to researchers, the core components of electronic components have their own stable operating temperature ranges. Generally speaking, if the temperature increases by 8°C to 10°C, the life of electronic devices will be reduced by half. In experiments, researchers applied this graphene film to mobile phone heat dissipation films instead of commercial graphite films, and found that the temperature at the mobile phone CPU can be controlled below 33°C, which is 6°C lower than the commercial graphite film.