Acoustic microswimmers present great potential for microuidic applications and targeted drug delivery. Here we introduce armoured microbubbles (size range, 10 − 20 µm) made by threedimensional microfabrication which allows the bubbles to last for hours even under forced oscillations. The acoustic resonance of the armoured microbubbles is found to be dictated by capillary forces and not by gas volume, and its measurements agree with a theoretical calculation. We further measure experimentally and predict theoretically the net propulsive ow generated by the bubble vibration. This ow, due to steady streaming in the uid, can reach 100 mm/s, and is aected by the presence of nearby walls. Finally, microswimmers in motion are shown, either as spinning devices or free swimmers. I.

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In this paper, we propose a novel full-field approach based on the fast Fourier transform (FFT) technique to compute mechanical fields in periodic discrete dislocation dynamics (DDD) simulations for anisotropic materials: the DDD-FFT approach. By coupling the FFT-based approach to the discrete continuous model, the present approach benefits from the high computational efficiency of the FFT algorithm, while allowing for a discrete representation of dislocation lines. It is demonstrated that the computational time associated with the new DDD-FFT approach is significantly lower than that of current DDD approaches when large number of dislocation segments are involved for isotropic and anisotropic elasticity, respectively. Furthermore, for fine Fourier grids, the treatment of anisotropic elasticity comes at a similar computational cost to that of isotropic simulation. Thus, the proposed approach paves the way towards achieving scale transition from DDD to mesoscale plasticity, especially due to the method’s ability to incorporate inhomogeneous elasticity.