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| Author | Transduction | Mechanical transfer | Cut-in wind speed (m/s) | Cut-out wind speed (m/s) | Maximum power (mW) | Wind speed at max power (m/s) | Dimensions | Power density per swept area (mW/cm2) | Advantages/disadvantages |
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| Rancourt et al. [35] | Electromagnetic | — | — | — | 130 | 11.8 | 4.2 cm in dia. | 9.38 | (i) High power generation efficiency at high wind speed.
(ii) At low wind speed, efficiency decreased sharply due to the friction in the generator and the internal electric resistance |
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| Howey et al. [36] | Electromagnetic | — | 3 | — | 4.3 | 10 | 3.2 cm in dia. | 0.535 | (i) Bearing loss and resistive generator loss limits the miniaturization of the turbine |
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| Priya et al. [22] | Piezoelectric | Contact via mechanical stopper | — | — | 10.2 | — | 12 bimorphs in a circular array, each of 6 × 2 × 0.05 cm3 | 0.0902 | (i) Proves the feasibility of efficiently harvesting low speed wind energy using piezoelectric materials.
(ii) Bimorphs are not vibrating in phase so the output has to be individually processed |
| Priya [37] | Piezoelectric | Contact via mechanical stopper | 2.1 | 5.4 | 7.5 | 4.5 | 10 bimorphs in a circular array, each of 6 × 2 × 0.06 cm3 | 0.0663 |
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| Chen et al. [38] | Piezoelectric | Contact via mechanical stopper | 2.1 | 6.2 | 1.2 | 5.4 | 5.08 × 11.6 × 7.62 cm3 | 0.0134 | (i) Easy to fabricate.
(ii) Space efficient with a rectangular-array arrangement of transducers.
(iii) Combined circuit can be used because all the bimorphs are vibrating in phase.
(iv) Power was much lower compared to the circular windmill |
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| Myers et al. [39] | Piezoelectric | Contact via mechanical stopper | 2.4 | — | 5 | 4.5 | 7.62 × 10.16 × 12.70 cm3 | 0.0388 | (i) Captured wind energy is increased by employing three fan blades |
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| Bressers et al. [40] | Piezoelectric | Contact-less via magnetic interaction | 0.9 | — | 1.2 | 4.0 | 16.51 × 16.51 × 22.86 cm3;
| 3.18 × 10−3 | (i) Minimizing the frictional loss by avoiding direct mechanical contact.
(ii) Prolonging the fatigue life of piezoelectric elements.
(iii) Lowering down the cut-in wind speed |
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| Karami et al. [41] | Piezoelectric | Contact-less via magnetic interaction | 2 | — | 4 | 10 | 8 × 8 × 17.5 cm3 | 0.0286 | (i) Introducing nonlinearity into the harvester.
(ii) Utilizing both nonlinear parametric excitation and ordinary excitation and helping to achieve low cut-in wind speed, high output power, and large operational range of wind speed |
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