Engineering Nanorobots: Chronology of Modeling Flagellar Propulsion

Abstract

Nanorobots are propitious to swim or fly compared with crawling and walking because of issues with desirable characteristics of high velocity, efficiency, specificity, controllability, and a simple propagation mechanism that can be realized with miniaturized parts. Inspired by the fact that microorganisms existing in nature function expeditiously under these circumstances, researchers have shown a great interest to conceptualize, model, analyze, and make micro-/nanosized swimmers (nanorobots) that can move in body fluids for applications such as targeted drug delivery, nanomedication, and in-viscera nanosurgery. The present work compiles modeling of physics as investigated since 1951 of flagellar propulsion in engineering nanorobots. Existing theories in flagellar propulsion such as resistive force theory, slender body theory, Kirchhoff rod theory, bead model, and boundary element method as well as progress in designing the propulsion system of a nanorobot are summarized, and various interdisciplinary aspects of realizing nanorobots and issues in moving nanorobots have been presented chronologically.

Purcell’s Three-Link Swimmer: Assessment of Geometry and Gaits for Optimal Displacement and Efficiency

“…The estimation of drag forces in low Re regime was studied by several authors, leading to the definition of theories and methods that apply different conditions to the object under study (see e.g., [29] and references therein). The main theories applied to the Purcell's swimmer are RFT and the slender body theory (SBT).…”

Asymptotic Dynamics of Magnetic Micro-Swimmers

“…where ψ > 0 is the conical angle between the magnetic field and its axis of rotation -note that this implies that the lab frame is chosen so that the magnetic field lies in the (e 1 , e 3 )-plane and that e 1 • B > 0 at time t = 0, which can be assumed without loss of generality. In this picture, taking a time derivative of (10) and using (5), yields…”

“…Understanding motion at low Reynolds number has been an active research topic for decades [1,2,3,4,5,6]. Intuitively, this corresponds to the limit of either very small bodies moving in water, or bodies in a very viscous fluid.…”

Propulsion of an artificial nanoswimmer: a comprehensive review

“…In a quest to mimic nature, many studies have been carried out on artificial nanoswimmers to imitate the propulsion of flagellated bacteria (Taylor 1951;Hancock 1953;Machin 1958;Leifson 1960;Keller & Rubinow 1976;Life at Low Reynolds Number 1977;Freitas 2005;Ummat et al 2005;Lauga & Powers 2009;Rathore & Sharma 2010;Deepak et al 2011;Rathore et al 2012;Kotesa et al 2013). The first published discussion about in vivo locomotion of a swimming nanorobot (Freitas 1999) addressed many issues, including movement through the blood stream, walking, traversing and swimming through various tissues and membranes, identification of defective cells, and swimming medical robots reaching a target area inside the human body.…”