Scientists at the Indian Institute of Technology (IIT) Patna have developed an innovative hybrid magneto-rheometer that promises to advance research and applications of magnetorheological (MR) fluids – smart materials widely used in sectors such as healthcare, aerospace, defence and industrial automation.
Supported by the Department of Science and Technology (DST), the new device offers a novel method to accurately evaluate the performance of MR fluids, which rapidly increase in viscosity when exposed to a magnetic field. This unique property enables the fluids to transmit controllable force, making them suitable for a wide range of adaptive technologies.
MR fluids are increasingly being used in applications such as brakes, clutches, shock absorbers, vibration control systems, dampers, actuators and medical devices. However, understanding their behaviour under real-world operating conditions has remained a challenge, particularly when the fluids are subjected to simultaneous compression and shear forces, a mode that has been relatively unexplored.
To address this gap, a research team led by Prof. Chiranjit Sarkar at IIT Patna developed nano iron powder-based MR fluids and designed a custom-built hybrid magneto-rheometer capable of measuring both the rheological (flow and deformation) and tribological (friction and wear) properties of these smart fluids under compression and shear, both in the presence and absence of a magnetic field.
The newly developed instrument generates a constant, high-strength magnetic field across the MR fluid sample while operating with comparatively low electrical current. This allows researchers to study the behaviour of iron-based MR fluids in combined compression and shear conditions, providing insights that conventional testing methods cannot offer.
According to the researchers, the prototype delivers a more comprehensive understanding of MR fluid performance, helping scientists optimise the design of smart materials for high-performance applications.
Beyond magnetorheological fluids, the hybrid rheometer is expected to benefit research on a broad range of viscoelastic materials used in industries such as polymers, pharmaceuticals, food processing, cosmetics and petrochemicals, where precise analysis of flow and deformation characteristics is essential.
The research, published in the journal Rheologica Acta, highlights how advances in material testing technology can accelerate innovation in smart materials. The scientists believe the new hybrid magneto-rheometer will provide researchers and industry with an advanced tool for developing next-generation adaptive, energy-efficient technologies based on high-performance magnetorheological fluids.
