fig5

From: Ionogels: materials design, properties, and emerging applications in advanced electrochemical and bioelectronic systems

Figure 5. Demonstrations of a pH-sensitive ionogel used in a biosensor and a self-healing ionogel. (A) The color responses of phenol red in the PPH ionogels to different pH buffer solutions. pH values: 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, and 8; (B) Optical image of the fast-response ionogel. pH value: 7; (C and D) RGB values (C) before and (D) after exercise in pH-responsive ionogel. (A-D) Reproduced with permission from ref.^[127], Copyright 2024, Royal Society of Chemistry; (E) The flexible keyboard was cut off and lost electrical functionality. Then, the stretchable keyboard healed and restored the electrical function after 1 h (scale bar: 2 cm); (E) is reproduced as a cropped excerpt from ref.^[123], under the CC BY 4.0 license; the depicted content was not altered. RGB: Red, green, and blue; PPH: pH-responsive material designation.