Office of Technology Transfer – University of Michigan

Electrorheological Fluid Discovery

Technology #4967

Electrorheological Fluid Discovery

This technology describes several new electrorheological (ER) fluids that perform similarly to other commercially available ER fluids under electric field, except with much smaller loadings of the electroactive component POSS (sulfonated polyhedral oligomeric silsesquioxane). ER fluids are fluids that can change from liquid like materials which can flow like milk to solid like structures under a certain electric field. ER fluids, as part of a class of materials generally referred to as smart suspensions, are used by automotive companies, defense agencies and in civil engineering field throughout the world. One drawback of the current ER fluids is that they exhibit unacceptably large viscosities in the absence of applied fields. This technology describes new ER fluids that show similar results to other commercial ER fluids under an electric field, while possessing low zero shear viscosity in the absence of the electric field. This low viscosity is comparable to that of silicone oil. This unique system should facilitate easier processing and utilization in industrial applications.

New Electrorheological POSS Systems

This technology describes new ER systems based on POSS/Polydimethylsiloxane (PDMS) mixtures. The POSS materials that give very strong ER effects are sulfonated POSS which consists of a hydrophilic (acidic/ionic) head and a hydrophobic (carbon chain) tail connected to an open POSS cage. The ER effect can be further enhanced by the addition of a polymeric material such as polystyrene beads. The main advantage of this technology over conventional ER fluid, is that it can achieve low viscosity in the absence of electric field while demonstrating strong ER activity with electric field, comparable to commercially available products. Another advantage is the use of low loadings of POSS materials, which can cut cost and facilitate wide-spread technology adoption.


  • Smart suspensions for automotive companies, defense agencies and civil engineering
  • Microfluidics
  • Temporary wound healing, soldering


  • Decreased material cost from low loadings
  • Low viscosity and can flow like silicone oil in the absence of an electric field,
  • Very strong electrorheological activity under the electric field, comparable to commercially available products
  • Chemical versatility and tunability