A Practical Guide to Analyzing and Reporting the Movement of Nanoscale Swimmers

Abstract

The recent invention of nanoswimmerssynthetic, powered objects with characteristic lengths in the range of 10–500 nmhas sparked widespread interest among scientists and the general public. As more researchers from different backgrounds enter the field, the study of nanoswimmers offers new opportunities but also significant experimental and theoretical challenges. In particular, the accurate characterization of nanoswimmers is often hindered by strong Brownian motion, convective effects, and the lack of a clear way to visualize them. When coupled with improper experimental designs and imprecise practices in data analysis, these issues can translate to results and conclusions that are inconsistent and poorly reproducible. This Perspective follows the course of a typical nanoswimmer investigation from synthesis through to applications and offers suggestions for best practices in reporting experimental details, recording videos, plotting trajectories, calculating and analyzing mobility, eliminating drift, and performing control experiments, in order to improve the reliability of the reported results.

Hydrogen Bonding Nanoarchitectonics of Organic Pigment-Based Janus Microrobots with Entering Capability into Cancer Cells

“…The MSD calculation in Figure B,D demonstrates a ballistic path when 5 wt % H 2 O 2 is employed as fuel. In addition, the increase in the slope of MSD in the case of UV light-supported motion suggests improved locomotion that is caused by enhanced diffusion. , Finally, characteristic trajectories of the microrobots are depicted in Figure C,F to demonstrate the influence of the addition of fuel.…”

Medical micro- and nanomotors in the body

“…The experimental and calculation procedures have been introduced previously 114 , 115 , 116 and were elaborated recently in a corresponding guide initiated by Wang et al. 117 .…”

“…Generally, for motors with large sizes (>1 μm), the calculation of instantaneous speed is carried out to evaluate the mobility 117 . First, the moving trajectories (including the x and y coordinates) can be acquired by optical microscopy and then plotted as a function of time.…”

“…However, it's worth noting that to get a reliable result, one should be very careful with the procedures of the measurement and MSD analysis 117 . In particular, one should note the drifting phenomenon of MNMs while tacking their trajectories.…”

Nanoswimmers Based on Capped Janus Nanospheres

“…Moreover, as the particle size decreases further, the relative Brownian forces increase. This presents challenges in the design [13] and characterization [14] of controllable mobile swimmers.…”