Fig. 1. (Color online) Summary of the review. Different kinds of materials with different sensing mechanism, thus for different sensors.

Fig. 2. (Color online) Graphene-based sensors. (a) Graphene-paper pressure sensors for detecting physiological signals. Reproduced with permission from Ref. [56], Copyright 2017, American Chemical Society. (b) Graphene-based multifunctional sensors. Reproduced with permission from Ref. [58], Copyright 2021, American Chemical Society. (c) Conformal electronic skin based on graphene. Reproduced with permission from Ref. [59], Copyright 2022, Wiley. (d) Mixed-modality speech recognition and interaction using a wearable AT. Reproduced with permission from Ref. [60], Copyright 2023, Nature Publishing Group.

Fig. 3. (Color online) MXene-based sensors. (a) Micro-force sensor combined with MXene and microchannel. Reproduced with permission from Ref. [68], Copyright 2020, Wiley. (b) Pressure sensor with electromagnetic shielding based on MXene of kirigami-inspired structure. Reproduced with permission from Ref. [69], Copyright 2021, American Chemical Society. (c) Self-healing strain sensor based on PU-TA@MXene Janus architecture. Reproduced with permission from Ref. [70], Copyright 2023, Wiley. (d) Piezoresistive sensor based on MXene/PEDOT:PSS. Reproduced with permission from Ref. [71], Copyright 2021, American Institute of Physics. (e) Pressure sensor with PAN/MXene nanofiber as the sensitive layer. Reproduced with permission from Ref. [72], Copyright 2022, Wiley. (f) Piezoelectric sensor with confined MXene/PVDF nanofiber. Reproduced with permission from Ref. [73], Copyright 2023, Springer.

Fig. 4. (Color online) BN-based sensors. (a) Humidity sensor with BN as sensitive layer. Reproduced with permission from Ref. [89], Copyright 2024, Wiley. (b) Pressure sensor based on BN combining with MXene. Reproduced with permission from Ref. [91], Copyright 2024, Wiley. (c) Piezoelectric sensor with hierarchical structure for cardiovascular monitoring. Reproduced with permission from Ref. [92], Copyright 2024, Wiley. (d) Composites of liquid metal@BN with highly thermal conductive. Reproduced with permission from Ref. [93], Copyright 2023, Elsevier.

Fig. 5. (Color online) MoS₂-based and MoSe₂-based sensors. (a) Tactile sensor based on MoS₂. Reproduced with permission from Ref. [113], Copyright 2016, Wiley. (b) Temperature sensor based on monolayer MoS₂ channel. Reproduced with permission from Ref. [114], Copyright 2022, American Chemical Society. (c) Strain and tempture sensor based on MoS₂ by inkjet printing. Reproduced with permission from Ref. [115], Copyright 2023, Wiley. (d) Humidity sensor with PVA/MXene nanofiber. Reproduced with permission from Ref. [116], Copyright 2021, Springer.

Fig. 6. (Color online) WS₂-based and WSe₂-based sensors. (a) Humidity sensor based on rGO-WS₂ heterojunctions. Reproduced with permission from Ref. [131], Copyright 2021, Elsevier. (b) Gas sensor for detecting NO₂. Reproduced with permission from Ref. [132], Copyright 2021, Elsevier. (c) Hybrid sensor for ethanol detection. Reproduced with permission from Ref. [133], Copyright 2020, Nature Publishing Group.