What are electrorheological materials?

Electrorheological (ER) materials are materials whose rheological properties, flow and deformation behavior in response to a stress, are strong functions of the electric field strength imposed upon them.

Why ER fluid is called smart fluid?

In absence of the electric field the particles exhibits properties like fluid and as the electric field is applied the particles behaves like solid. These fluids which change its physical properties like viscosity due to application of electric field are called electro rheological (ER) fluids or smart fluids.

What is ER fluid made of?

ER fluids are typically comprised of polarizable or semi-conducting particles suspended in a carrier liquid. In the absence of an electric field, the particles are freely suspended in a liquid medium, and exhibit properties similar to those of Newtonian fluids.

How to make ER fluid?

ER fluids are a type of smart fluid. A simple ER fluid can be made by mixing cornflour in a light vegetable oil or (better) silicone oil.

Is toothpaste a non Newtonian fluid?

Many salt solutions and molten polymers are non-Newtonian fluids, as are many commonly found substances such as custard, toothpaste, starch suspensions, corn starch, paint, blood, melted butter, and shampoo.

What are electro Rheostatic materials used for?

Electro-rheostatic (ER) and magneto-rheostatic (MR) ER- mainly been developed for use in clutches and valves, as well as engine mounts designed to reduce noise and vibration in vehicles.

How do electro Rheostatic materials work?

Electro-rheostatic (ER) and magneto-rheostatic (MR) materials are fluids, which can experience a dramatic change in their viscosity. (thickness or consistency) Can change from a thick fluid (similar to motor oil) to nearly a solid substance within the span of a millisecond when exposed to a magnetic or electric field.

What are ER and MR fluids?

Electrorheological (ER) and magnetorheological (MR) fluids, which can be transformed from the liquid state into the solid state in milliseconds by applying an electric or a magnetic field, are smart fluids having the potential to revolutionize several industrial sectors.

Is milk a Newtonian?

Normal milk behaves as a Newtonian liquid and its viscosity is affected by temperature, fat content, protein content, total solids, and solid-to-liquid fat ratio (Fernandez-Martin, 1972; Randhahn, 1973; Bloore and Boag, 1981; Langley and Temple, 1985; Velez-Ruitz and Barbosa-Canovas, 1998, 2000).

Can Oobleck stop a bullet?

The materials reminded her of Oobleck, a non-Newtonian fluid — which thickens when force is applied — made of cornstarch and water and named after a substance from a Dr. Seuss book, and she became interested in producing a material that would stop bullets without shattering.

Where is Mr fluid used?

The fluid has applications in various fields such as automotive industry, household applications, prosthetics, civil engineering, hydraulics, brakes and clutches, etc. Also there is a possible application of the fluid in reducing the effect of Gun Recoil.

What are the properties of a magnetorheological material?

Magnetorheological materials (fluids) (MR) are a class of smart materials whose rheological properties (e.g. viscosity) may be rapidly varied by applying a magnetic field. Under influence of magnetic field the suspended magnetic particles interact to form a structure that resists shear deformation or flow.

Who are the leading experts in electrorheological fluid?

Youngwook P. Seo, Yongsok Seo, in Reference Module in Materials Science and Materials Engineering, 2020

How are polymers used in electrorheological fluid?

All these additives possess a high dielectric constant that enables ionic charge carriers to migrate with the electric field. Polymers used in ER fluids include ionic and electronic semiconductors, polyelectrolytes, rigid-rods, and liquid crystal polymers.

What are the properties of magnetic and electro rheological fluids?

Magnetic and electro-rheological fluids have magnetic and electric properties, respectively, so that particles do not necessarily rotate with the local velocity of the flow field, but with a certain angular velocity which depends on the magnetic or electric field.

Why are ferroelectric particles used in electrorheological fluid?

It is the presence of charge carriers, electrons, and protons that make the particles in these fluids highly polarizable. Ferroelectric particles such as BaTiO 3 and SrTiO 3 are also typically used in ER fluids because of the high dielectric constants of these materials.