A way to harvest mechanical energy: Flexible Piezolelectric Nanogenerators

In the GREMAN laboratory, conducting extended work on zinc oxide (ZnO) nanowire generators, a recently completed PhD thesis sheds light on a potential industrialized production of these nanowires. In the framework of the Energy for Smart Objects (EnSO) European project, Camille Justeau worked on a low-cost manufacturing process of a ZnO nanowire-based nanogenerator, an energy transducer capable of converting mechanical energy into electricity. This new type of transducer, once associated with devices capable of storing energy (a micro-battery for example), will form an Autonomous Energy Micro-Source (AMES).

The ZnO nanowires were obtained using a low-temperature (<100°C) chemical process, called hydrothermal synthesis. ZnO is used for its piezoelectric capacities (the property of materials to polarize and produce electricity when bended or compressed) and its semi-conductor properties. Under precise conditions, a chemical reaction allows to grow on a substrate a “carpet” of millions of aligned nanowires, about 1 micrometer long, with excellent crystalline properties. Once the reaction is ended, the ZnO formation on the substrate is covered by polymer layers, including a protection polymer that makes the nanogenerator flexible while protecting it from any damage. Once pressure is applied on the nanogenerator, the nanowires inside are compressed and produce an electric potential, which supplies an external electrical circuit.

Once this device is advanced enough, the nanogenerator will be capable of supplying low power sensors in direct contact with a moving body, a natural (water flow, a heartbeat…) or an industrial (a moving machine or vehicle) energy source. The concept, capable to adjust to specific user needs, opens up a vast field of possible applications that are yet to be discovered.

Read more:

C. Justeau, T. Slimani Tlemcani, G. Poulin-Vittrant, K. Nadaud, D. Alquier, A comparative study on the effects of Au, ZnO and AZO seed layers on the performance of ZnO nanowire-based piezoelectric nanogenerators, Materials 12 (2019) 2511. Click here for more details.

K. Nadaud, G. Poulin-Vittrant, D. Alquier, Effect of the excitation waveform on the average power and peak power delivered by a piezoelectric generator, Mechanical Systems and Signal Processing 133 (2019) 106278. Click here for more details.

T. Slimani Tlemcani, C. Justeau, K. Nadaud, G. Poulin-Vittrant, D. Alquier, Deposition time and annealing effects of ZnO seed layer on enhancing vertical alignment of piezoelectric ZnO nanowires, Chemosensors 7(1) (2019) 7. Click here for more details.
A. S. Dahiya, F. Morini, S. Boubenia, K. Nadaud, D. Alquier, G. Poulin-Vittrant, Organic/Inorganic hybrid stretchable piezoelectric nanogenerators for self-powered wearable electronics, Advanced Materials Technologies (2017) 1700249, 11 pp. Click here for more details.

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