fig3

Figure 3. Applications of biotic iontronics in closed-loop signal processing systems. (A) Biotic iontronics enables multimodal signal sensing based on a hydrogel-based electronic skin, detecting thermal, mechanical, and chemical signals^[26]; Reproduced with permission of ref. 26, Copyright 2025, The American Association for the Advancement of Science; (B) Prosthetic control system enhanced by gel-based electrodes, with further improvements possible through the application of biotic iontronics^[30]; Reproduced with permission of ref. 30, Copyright 2023, American Chemical Society; (C) Hydrogel-based brain-machine interface achieving neural activity recording^[36]; Reproduced with permission of ref. 36, Copyright 2021, Springer Nature under CC BY 4.0 license http://creativecommons.org/licenses/by/4.0/.