Highly Efficient Miniaturized Magnetorheological Valves Using Electropermanent Magnets

Abstract

Fluidic systems enable actuation in various applications, such as automotive, medical, and industrial robotics. Miniaturized valves constitute a fundamental controlling element of modern fluidic systems, intriguing the interest of many researchers. This letter presents the design, implementation, and experimental validation of a miniaturized magnetorheological valve. The valve is highly efficient due to its capability of sustaining high loads with low energy consumption. This work includes the estimation strategy for the sustained load. Magnetorheological fluid is used both as an actuation fluid and as control medium. The inner iron core of the traditional magnetorheological valve is replaced with an AlNiCo-5 rod. The latter provides the possibility of magnetic energy storage, without continuous power supply. This changes the actuation mechanism from an electromagnet to an electropermanent magnet. The valve's capability to sustain pressure up to 1010 kPa, for a volume of 353 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> , is demonstrated experimentally. The fluid flow rate when the valve is open is 459 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> /s for a pressure difference of 993 kPa. The corresponding power consumption is negligible in steady-state condition, while consuming 15.3 mJ when activated and 6 mJ when deactivated. The experimental results also validate the possible tunability of the pressure sustaining capability of the valve.