Fig. 1: Bioinspired triboelectric droplet sensor.
From: Bioinspired triboelectric droplet sensor for ammonia monitoring

a Schematic diagram of alveolar structural characteristics and oxygen diffusion process, hemoglobin (Hb). b Schematic diagram of the structural features of the triboelectric droplet sensor and ammonia diffusion process, illustration (ii) depicts the chemical reaction of ammonia dissolving in water and the influence of ammonium ions on charge transfer at the liquid-solid interface, fluorinated ethylene propylene (FEP).