fig2
Figure 2. The mechanisms of (A) Piezoelectric[34], Copyright 2023 MDPI; (B) Triboelectric[35], Copyright 2018 WILEY-VCH; (C) Capacitive[33], Copyright 2022 MDPI; (D) Resistive[36], Copyright 2019 MDPI; (E) Electrochemical[13], Copyright 2022 Springer Nature; (F) Thermoelectric[37] sensors, Copyright 2020 Springer Nature.
