Multiresonant Frequency Piezoelectric Energy Harvesters Integrated with High Sensitivity Piezoelectric Accelerometer for Bridge Health Monitoring Applications

Figure 25

Fabrication process steps (not to scale).

(a) RCA cleaning

(b) Wet oxidation and top oxide removal

(c) ZnO film formation

(d) Aluminium deposition

(e) Patterning ZnO, aluminium, and device silicon

(f) SiO₂ patterning for back etching

(g) Back etching by DRIE to realize cantilever beam mass

(h) Packaged device