The ink is made of small sheets of copper and scientists claim that it can be used for writing functioning and flexible electric circuit on a conventional printed paper. The conductive ink could pave the way for a wide range of new gadgets as well.

To have a versatile conductive ink, researchers tried copper nanosheets, which are inexpensive and highly conductive. They made copper nanosheets coated with silver nanoparticles in the lab and incorporated this material into an ink pen, using it to draw patterns of lines, words and even flowers on regular printer paper.

To show that the ink could conduct electricity, the scientists studded the drawings with small LED lights that lit up when the circuit was connected to a battery.

To test the ink's flexibility, they folded the papers 1,000 times, even crumpling them up, and showed that the ink maintained 80 to 90% of its conductivity, added the research funding by the National Natural Science Foundation of China.