fig6

Figure 6. Machine learning-enhanced P-HMIs. (A) Overall illustration of process and potential applications of machine learning-enhanced piezoelectric acoustic sensors. Reproduced with permission from ref.^[91]. Copyright 2019, Wiley. (B) Visualized speaker embeddings with t-SNE. Each speaker is marked by its color and the text indicates pronounced digits. Reproduced with permission from ref.^[92]. Copyright 2018, IEEE. (C) Artificial skin consisting of sensing, perception and encapsulation layers. Reproduced with permission from ref.^[93]. Copyright 2020, Wiley. (D) Architecture of neural network model for the classifier used for object recognition. Reproduced with permission from ref.^[94]. Copyright 2020, IOP Publishing Ltd. (E) Schematic diagram of piezoelectric output voltage signals when a password is entered. (F) Image of piezoelectric panel for user authentication. Reproduced with permission from ref.^[95]. Copyright 2021, IEEE. (G) Schematic illustration of HMIs with traditional and closed-loop HMI systems. Reproduced with permission from ref.^[97]. Copyright 2022, American Association for the Advancement of Science.