Manufacturing complex fluids industrially often involves mechanical forces that introduce internal stress and damage microscopic structures, compromising a material’s integrity and functionality. While rheo-optical techniques are available for evaluating structure–stress relationship, they do not accurately link mechanical stresses to observable optical changes under extensional stress. Addressing this, researchers from NITech, Japan, have now developed a novel technique for simultaneous measurement of macroscopic extensional stress and microscopic changes to optical properties during uniaxially extensional flow.

Encapsulated microbubbles (EMBs) are vital in ultrasound imaging and emerging drug-delivery technologies. To analyze their behavior in blood, researchers from Nagoya Institute of Technology developed a detailed numerical framework that tracks the dynamics of EMBs near rigid walls in viscoelastic fluids. By combining the Oldroyd B model with the boundary element method, they demonstrated how shell thickness, viscoelasticity, and ultrasound parameters influence EMB dynamics, providing key insights for their safer design.