Novel Electroactive Polymer-based Flow Sensors for Automotive Systems


Description of Technology


Michigan State University’s sensing technology enables potential commercial applications in a broad range of industrial applications where information is needed on a combination of fluid/gas flow rates (e.g., in a line), along with the real-time density/viscosity variation of those fluids or gases. The invention uses electroactive polymer composites in various configurations (e.g., cantilevered or clamped). With these composites, a flexing of a polymer in response to fluid or gas flow causes a migration of positively charged ions (i.e., cations) in the polymer and a resulting electrical field. The measurement of the electrical field (including peak signal and frequency spectrum of the damped oscillations) is well-correlated with the fluid properties of the flow (e.g., flow speeds) as well as properties of the flow media, such as density and viscosity. The invention lends itself to inexpensive sensors for the real-time variation of ethanol in gasoline and for sensors providing other real-time information on fluid flow rates and densities for industrial process applications.


Key Benefits

  • Versatility: The polymer sensors are able to measure multiple flow characteristics (e.g., density, viscosity, flow rate, cyclic variations, and flow start/stop times).
  • Simplicity: The technology uses direct mechano-electrical transduction resulting from flexed polymers.
  • Flexibility: The sensors are able to measure flows over a wide range of liquid/gas flow speeds.
  • Low cost: The polymer sensing technology is expected to be significantly less expensive than existing alternatives, enhancing the commercial practicality of obtaining and incorporating additional sensor information relating to fuel flows and other fuel characteristics.
  • Amenability to miniaturization: Associated with the small dimensions, the sensors are also lightweight.




This invention has potential industrial applications where the estimated commercial price of the MSU sensor is significantly less than existing sensors. One such application is in electronic control modules (ECMs) in automobile engines using ethanol fuels.


Patent Status


Patent pending




Guoming Zhu, Xiaobo Tan, David Hung


Tech ID




Patent Information:

For Information, Contact:

Brian Copple
Technology Manager
Michigan State University