|
| Piezoelectric transducer classification | Design | Frequency/frequency band (Hz) | Maximum power density (mW/cm3) | Advantage | Disadvantage |
|
| Cymbal transducers | 2 × 32 × 32 mm PZT ceramic confined between steel caps [28] | 5 | 1.03 | Enhanced horizontal polarization | Prone to polarization-induced cracks |
| ∅8 mm piezoelectric disk sandwiched between two nylon disks [31] | NA | NA |
| ∅29 mm piezoelectric disk, 1 mm thick [29] | 50∼150 | 59.07 |
| ∅29 mm piezoelectric disk, 1 mm thick [32] | 100∼200 | 78.77 |
| ∅35 mm piezoelectric disk confined between two ∅35 mm steel discs [33] | 1.19 | 0.31∼1.37 |
| ∅35 mm PZT disk confined between two ∅35 mm metal endcaps [34] | 5∼3,000 | ∼1,000.64 |
| ∅32 mm PZT disk, 2 mm thick [35] | 20 | 0.75 |
|
| Cantilevered transducers | 15 × 15 × 1.5 mm piezoelectric disk attached on a steel cantilever [36] | 72 | 0.0003∼0.0008 in the vertical direction and 0.001 in the horizontal direction | Convenient to polarize piezoelectric layers in the “31 mode” | Redundant piezoelectric materials in the nonstress zone on the cantilever |
| ∅1.5 mm PZT disk [37] | 0.9 | 1.25 |
| 2 × 2 × 0.0047 mm piezoelectric film on 1.5 µm thick cantilever [38] | 11.5∼14.5 | NA |
|
| Other transducers | Multiple ∅31.60 mm PZT disks with the thickness of 14.35 mm embedded in the energy harvester device [15] | NA | 0.78 | Enhancing energy efficiency with improved and flexible designs | — |
| Curved piezoelectric layers [30] | 64 | NA |
| Stacked layers with the piezoelectric film [39] | NA | 360∼2,400 |
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