Designing Electrolysis Ion Display on Everyday Open Wet Surfaces

This pictorial presents a novel method to render color patterns using electrolysis applied onto open wet surfaces. By implementing electrodes within a wet object and electrifying them, electrolysis can occur and generate ions. We designed a color-forming display using color indicators reacting with such ions. This method can display patterns according to the shape of the electrode. By reversing the polarity of the electrodes and generating reversed-polarity ions, it is possible to fade the existing pattern and display a contrasting color. The proposed method does not require moving parts; thus, it is low cost and easy to compact. Also, some foods containing pH-reactive substances can be used as a display medium. Therefore, the proposed method can realize an information display using various objects common in everyday life, such as decor or food.