Dr. Marcus HultmarkFounder, Tendo Technologies and Associate Professor,Department of Mechanical and Aerospace EngineeringPrinceton University AZoSensors speaks with Dr. Marcus Hultmark, an associate professor in the Department of Mechanical and Aerospace Engineering at Princeton University. Marcus led a team that found a revolutionary new approach to measuring flow rates. What makes the EFV sensor different from other available flow sensors? The way EFV measures the flow is different from other sensors. Instead of relying on thermal effects or pressure, which are the most common methods, it relies on viscous forces. It measures these viscous forces through a sensing element that looks much like a typical strain gage, but without being mounted on a membrane.