Fig. 3: Mechanism of rapid hydrovoltaic ion sensing.
From: Ion transport-triggered rapid flexible hydrovoltaic sensing
a Schematic diagram of the semi-dry hydrovoltaic nanochannel at the end of a Voc signal cycle. b Schematic diagram showing dynamics of water and ions in the semi-dry nanochannels when applying a new water droplet (Stage I). An unbalanced force exists: \({F}_{c}+{F}_{{eva}}\gg {F}_{E}+{F}_{\nu }\). c Schematic diagram of the nanochannel when the Voc signal starts to decrease (Stage II, t = 0.17 s to t = 40 s) because of the existence of unbalanced force that \({F}_{E}+{F}_{\nu } > {F}_{{eva}}+{F}_{c}\). d Schematic diagram of the nanochannel when the Voc signal is relatively stable (Stage II, t = 40 s to t = 60 s) due to the existence of force balance \({F}_{E}+{F}_{\nu }\approx {F}_{{eva}}+{F}_{c}\).
