Structural instabilities: from energy harvesting to tunable structures

Intriguing morphologies and surface patterns in nature at different scales from wrinkles on skins of mammalians, plants, and fruits to crumpled membranes of blood cells have inspired a big body of research in soft matter instabilities. In this project, we extend the application of soft matter instabilities to kinetic energy harvesting and tunable structures.

Conventional vibratory energy harvesters usually suffer from narrow bandwidth and are very inefficient at small scale for low frequency harvesting. Here, to improve the harvesting effectiveness, we propose to exploit surface instability or in general instability in layered composites, e.g. wrinkling, where intriguing morphological patterns with large strain are formed under compressive loads. The induced large strains which are independent of the excitation frequency, could be exploited to give rise to large strains in an attached piezoelectric layer to generate charge and, hence energy. On the other hand, the mutual feedback between the structure and the transduction mechanism delays and could eventually prevent the instability if the feedback is too strong. This way we could control the instability, and hence, extend the application of the aforementioned idea from energy harvesting to a whole new level of tunable material/structures with a myriad of applications

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