Swimming by means of non-Newtonian fluids – AIP.ORG

Conventional rheometric units, equivalent to cone-and-plate rotational rheometers, have to extract a fluid from its supply to measure it, a course of that may alter some fluid properties or may be unattainable. But what if researchers may convey a tool to the fluid as an alternative?

Chiu et al. simulated and engineered a tethered swimmer that makes use of propulsive forces to find out rheological parameters that quantify a fluid’s diploma of elasticity of a non-Newtonian fluid.

“The tethered swimmer can measure the zero-shear first normal stress coefficient, which is not achievable on standard benchtop rheometers because of limited sensitivity,” writer Selena Chiu stated.

To develop this machine, the researchers first established switch capabilities — equations that relate the propulsion of the swimmer to the fluid’s properties.

The swimmer itself is product of two spheres magnetically coupled to a motor, all linked to a digital scale that measures propulsive power. From there, the researchers can use their switch capabilities to find out the rheometric properties.

“Currently, the device is just made from off-the-shelf components,” Chiu stated. “So anyone can make this if they know how to put together Arduino boards and use a 3D printer.”

While their machine solely measures just a few rheometric properties of non-Newtonian fluids, the researchers hope to develop its capabilities for various fluids and properties. They would wish to develop extra switch capabilities, which might develop the chances for rheological measurements.

“If we can further develop the device, then it could be used in situ,” Chiu stated. “If we could, say, install the device in a reactor and run it while the processes are running, then we would be able to have time-resolved measurements.”

Source: “Measuring the properties of a viscoelastic fluid using a tethered swimmer,” by Selena Chiu, Adil Jussupov, Cody Moose, Gerald G. Fuller, Manu Prakash, and Eric S.G. Shaqfeh, Journal of Rheology (2026). The article may be accessed at .