fig7

Figure 7. Outlook for P-HMIs: from piezoelectric materials to future applications. Reproduced with permission from ref.^[98]. Copyright 2008, Elsevier. Reproduced with permission from ref.^[99]. Copyright 2009, AIP Publishing LLC. Reproduced with permission from ref.^[100]. Copyright 2020, Elsevier. Reproduced with permission from ref.^[101]. Copyright 2019, Elsevier. Reproduced with permission from ref.^[102]. Copyright 2018, Wiley. Reproduced with permission from ref.^[103]. Copyright 2019, Springer Nature.