Sustainable Soft Electronics Combining Recyclable Metal Nanowire Circuits and Biodegradable Gel Film Substrates

Direct disposal of used soft electronics into the environment can cause severe pollution to the ecosystem due to the inability of most inorganic materials and synthetic polymers to biodegrade. Additionally, the loss of the noble metals that are commonly used in soft electronics leads to a waste of scarce resources. Thus, there is an urgent need to develop "green" and sustainable soft electronics based on eco-friendly manufacturing that may be recycled or biodegraded after the devices' end of life. Here an approach to fabricating sustainable soft electronics is demonstrated where the expensive functional materials can be recycled and the soft substrate can be biodegradable. A stretchable agarose/glycerol gel film is used as the substrate, and silver nanowires (AgNWs) are printed on the film to fabricate the soft electronic circuits. The mechanical and chemical properties of the agarose/glycerol gel films are characterized, and the functionality of the printed AgNW electrodes for electrophysiological sensors is demonstrated. The demonstration of the biodegradability of the agarose/glycerol and the recyclability of AgNWs points toward ways to develop sustainable and eco-friendly soft electronics. Electronic waste (e-waste) from soft electronics can have enduring detrimental effects on the environment. This work aims to mitigate e-waste by combining biodegradable and recyclable materials. A class of soft electronic circuits is presented that use stretchable agarose/glycerol gel film as the substrate and conductive patterns from silver nanowires as the electrodes. The biodegradability of the agarose and recyclability of silver nanowires can enable the manufacturing of sustainable soft electronics.image