Ionogel Microphones Detect Underwater Sound with Directivity and Exceptional Stability

Engineering the electric double layer (EDL) next to the electrode surface as an impedance-dominating location inside an ionogel provides us an opportunity to detect sound underwater, especially sound from different directions. In response to these vector stimuli, subtle changes in the interface/EDL were easily captured by high-frequency alternating current (AC) modulations. In contrast to capacitive mechanisms under direct current (DC)...