Hydrodynamic Impedance Correction for Reduced‐Order Modeling of Spermatozoa‐Like Soft Micro‐Robots

Abstract

Hydrodynamic interactions play a key role in the swimming behavior and power consumption of bio-inspired and biomimetic micro-swimmers, cybernetic or artificial alike. Bio-inspired robotic micro-swimmers require fast and reliable numerical models for robust control in order to carry out demanding therapeutic tasks as envisaged for more than 60 years. The fastest known numerical model, the resistive force theory (RFT), incorporates local viscous force coefficients with the local velocity of slender bodies in order to find the resisting hydrodynamic forces, however, omitting the induced far-field. As a result, the power requirement cannot be predicted accurately. The question of predicting and supplying the necessary power is one of the obstacles impeding the micro-robotic efforts. In this study, a novel strategy is proposed to improve the RFT-based analysis, particularly for spermatozoa and spermatozoa-inspired micro-swimmers with elastic slender tails, in order to present a practical solution to the problem. The postulated analytical improvement and the associated correction coefficients are based on hydrodynamic impedance analysis of the time-dependent solution of three-dimensional (3D) Navier-Stokes equations incorporated with deforming mesh and subject to conservation of mass.

Learning-based intelligent trajectory planning for auto navigation of magnetic robots

“…However, the precise modeling between the magnetic actuation system and the resulting motion is challenging because the magnetically controlled motion always involves many delays including motion inertia ( Fruchard et al, 2019 ; Meng et al, 2019 ), hardware delay, and software delay. The inertia delay is defined as the motion of the motile robot being affected by the previous moving status ( Tabak, 2018 ; Tabak, 2019 ). Therefore, it will affect the modeling because the robotic motion is affected by the previous states.…”

Understanding Robustness of Magnetically Driven Helical Propulsion in Viscous Fluids Using Sensitivity Analysis

“…The motion in a confined environment (lumen) filled with glycerin has been predicted by the model and the step‐out frequency has been also estimated. [ 24 ] Additionally, a control technique has been defined to account for the flow near the boundaries of the lumen by modifying the resistance matrix; incorporating an additional stiffness correction factor. Recently, Tang et al.…”

“…The motion in a confined environment (lumen) filled with glycerin has been predicted by the model and the step-out frequency has been also estimated. [24] Additionally, a control technique has been defined to account for the flow near the boundaries of the lumen by modifying the resistance matrix; incorporating an additional stiffness correction factor. Recently, Tang et al have wirelessly controlled nanorobots and demonstrated precise maneuvers within complex in vitro and in vivo environments, and investigated their kinetic behavior based on the geometric properties of their body and the effects imparted by nearby solid boundaries.…”