The aim is to design and study the smart macro/micro-scale structures with the intentionally controllable shape deformations and strain gradients which can enable to precisely control both the flexo and piezo effects within a given structure. To this end the unique properties of SMAs (i.e., shape memory effect and superelasticity), amplified flexoelectric effect of 3D interconnected porous polymers with porosity gradients, and/or amplified flexoelectric effect due to inhomogeneities in nonperiodic perovskite multilayers will be utilized. By combining these types of materials, a new family of the multifunctional structures offering enhanced electrical response and other unique properties would be designed and built. The synergy of combined electro-mechanical-thermal coupling can find application in, for example, the shape-shifting devices that can respond to their environment in a new and innovative ways. It could also enable the creation of novel sensing/energy harvesting devices with an increased sensitivity, efficiency, and design flexibility.
Scheme of the piezoelectric response in the functional layer subjected to tension, combined piezoelectric and flexoelectric response on the wrinkled functional film
Finite element model of a mechanically loaded right half of a nano crack with an electric potential appearing at its tip due to the flexoelectric effect. The flexoelectric effect is associate with strain gradients appearing in the fracture dominant zone Λf proportional to an intrinsic material length parameter such as the material lattice dimension.
Projects
GAČR 25-16701S: Smart structures with functional properties utilizing electro-mechanical-thermal coupling between layers of ferro/flexo/SMA composites, submitted
Publications
PROFANT, T.; SLÁDEK, J.; SLÁDEK, V. Asymptotic solutions for interface cracks between two dissimilar flexoelectric materials. MECHANICS OF ADVANCED MATERIALS AND STRUCTURES, 2024, 31(1) 64-78. ISSN: 1537-6494.
PROFANT, T.; SLÁDEK, J.; SLÁDEK, V.; KOTOUL, M. Assessment of amplitude factors of asymptotic expansion at crack tip in flexoelectric solid under mode I and II loadings. INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES, 2023, 269, 112194. ISSN: 1879-2146.
PROFANT, T.; SLADEK, J.; SLADEK, V.; KOTOUL, M. Asymptotic solution for interface crack between two materials governed by dipolar gradient elasticity: Amplitude factor evaluation. THEORETICAL AND APPLIED FRACTURE MECHANICS, 2022, 120, 103378. ISSN: 0167-8442.
SLÁDEK, J.; SLÁDEK, V.; HRYTSYNA, M.; PROFANT, T. Influence of flexoelectricity on interface crack problems under a dynamic load. Engineering Fracture Mechanics, 2023, 288, 109353. ISSN: 0013-7944.
SLADEK, J; SLADEK, V; HRYTSYNA, M; PROFANT, T. Application of the gradient theory to interface crack between two dissimilar dielectric materials. ENGINEERING FRACTURE MECHANICS, 2022, 276B, 108895. ISSN: 0013-7944.
In addition to the mentioned research topics, the group also participates in solving sub-problems related to new concepts of using metamaterials for smart morphing of aircraft wings solved within the BAANG project of the Horizon-Widera program https://baang.eu/.
Contact person
prof. RNDr. Michal Kotoul, DrSc.