Dr Marina Terzi,
Le Mans University
Directed drift of a deformable axisymmetric particle on a vibrating substrate
Abstract:
It is known that solid particles posed on a vibrating substrate can move on it. Under certain conditions, the particle can drift in a particular direction. Such drift can be potentially used to activate components of micro-devices, to transport powder and to clean dry surfaces from dust. The drift can be initiated e.g. by exciting Rayleigh acoustic wave in the substrate which causes friction at the contact between particle and substrate, which, in turn, creates an asymmetry between the direction of the wave and against it. This talk is about the required wave characteristics to obtain the directed drift as well as about its possible directions. While a material point is capable of sliding only in the direction of the wave, our model of deformable particle predicts particle drift in the both directions. Contact of an axisymmetric deformable particle with an elastic half-space is described via the known Hertz-Mindlin solution upgraded into a so-called method of memory diagrams (MMD) valid for an arbitrary acoustic excitation. The drift direction is determined by the direction of the friction force in a low normal compression phase that fosters slip, in accordance to the Coulomb friction law. In closing, I will talk about the experimental validation attempts and the related challenges.
Biography:
Dr Marina Terzi joined Laboratory of Acoustics Le Mans University (LAUM) as a postdoc in 2022. She obtained her BSc in Physics and MSc in Physical and Applied Acoustics in Moscow State University in 2016 and 2018, respectively, while doing research in Laboratory of Industrial and Medical Ultrasound. She received her PhD in Acoustics in Université Hauts de France in 2022. Her current research is focused on vibroacoustic particle manipulation, but she also has background in nondestructive testing, ultrasonic imaging, vortex beam generation, guided waves in boreholes for carbon sequestration, and problems related to contact acoustic nonlinearity.