Desktop printing of flexible electronic circuits on paper using liquid metal ink is demonstrated in Scientific Reports this week. The work may pave the way for a simple, low-cost method for printing paper electronics.
Paper is an attractive material for making flexible electronics as it is cheap and easy to work with; however, electrical inks are difficult to print onto paper, which can affect their conductivity. Jing Liu and colleagues have overcome some of the issues that have impeded reliable printing of circuits. They improve the adhesion by modifying the ink, designing new printing machinery and selecting specially coated paper that offer the best surface for ink to attach to. The whole printing process can be performed at room temperature, and the inks can be reused, which adds to the ‘green’ appeal of this technique.
The authors propose that their method for making flexible electronics could be applied to several technologies, such as making radio-frequency identification tags for books.