Measuring DNA Microswimmer Locomotion in Complex Flow Environments

TL;DR

This paper introduces a novel method to measure and analyze the locomotion of DNA microswimmers in complex fluid environments, accounting for flow-induced motion to better understand their navigation capabilities.

Contribution

The study develops a tracking technique using fiducial microspheres to isolate microswimmer motion from environmental flow effects, enabling accurate analysis in dynamic conditions.

Findings

Successfully tracked microswimmer trajectories in complex flows

Demonstrated the method with multiple microswimmers in different flow scenarios

Quantified the microswimmers' field-driven translation relative to fluid flow

Abstract

Microswimmers are sub-millimeter swimming microrobots that show potential as a platform for controllable locomotion in applications including targeted cargo delivery and minimally invasive surgery. To be viable for these target applications, microswimmers will eventually need to be able to navigate in environments with dynamic fluid flows and forces. Experimental studies with microswimmers towards this goal are currently rare because of the difficulty isolating intentional microswimmer motion from environment-induced motion. In this work, we present a method for measuring microswimmer locomotion within a complex flow environment using fiducial microspheres. By tracking the particle motion of ferromagnetic and non-magnetic polystyrene fiducial microspheres, we capture the effect of fluid flow and field gradients on microswimmer trajectories. We then determine the field-driven translation of these microswimmers relative to fluid flow and demonstrate the effectiveness of this method by illustrating the motion of multiple microswimmers through different flows.