Flexible Conductors from Brown Algae for Green Electronics

In this paper a novel approach is presented to prepare flexible and transparent conducting films, whose components can be separated and recovered via a recycling process. The fabrication method is based on low power sputtering of ultrathin gold layers on sodium alginate free‐standing films. The resulting foils are thin, easy to handle, and shape, while showing good conductive properties. In particular, they show excellent resistance to mechanical stress, like bending or rubbing, and are highly stable in ambient atmosphere over several months. Therefore they may represent a very promising candidate to be employed in green electronics, thanks to the reduced energy consumption required for their fabrication, the absence of toxic components or chemicals that are derived from oil, and the possibility to disassemble the devices at the end of their life in environmentally friendly conditions. A marine algae biopolymer is metallized to realize flexible circuit boards that are easy to disassemble for recycling the individual components. Strong and tight metal lines are obtained by sputtering without pretreatments. Controlling metal thickness gives the optimal compromise between conduction and transparency for opto‐electronic applications. An effective alternative to nanocellulose sheets is demonstrated.