A Nonvolatile Switchable-polarity EPM Valve

A research team from the University of Edinburgh, led by Adam A. Stokes with Bingchao Wang and Jonah Mack, has published a breakthrough paper on arXiv introducing the Switchable-polarity ElectroPermanent Magnet (S-EPM) valve. This fundamentally new architecture addresses a core limitation in fluidic systems: the requirement for continuous power input to maintain valve states. Traditional pneumatic and fluidic control systems rely on valves that need constant actuation, creating substantial thermal overhead and architectural constraints. The S-EPM solves this by using a composite magnet assembly that can be switched between two stable magnetic configurations with just a brief electrical pulse, then maintains that state indefinitely without power.

The technical innovation lies in reconfiguring internal flux pathways within the magnet assembly, allowing deterministic polarity reversal through transient excitation. When integrated into a compact pinch-valve design, this enables robust control of both pneumatic and liquid media. The researchers demonstrated practical applications including a nonvolatile six-port routing array that provides address-based routing and programmable compositional control. Unlike standard mechanically coupled rotary valves, these systems can achieve individual port isolation and create logic-embedded fluidic networks like decoders and hierarchical distribution modules.

This work establishes what the researchers call "state-encoded magnetic control" for fluidic systems. By embedding functionality in persistent magnetic states rather than continuous power or static plumbing, the S-EPM valve enables digital fluidics that can maintain complex routing configurations without energy consumption. The architecture offers scalability advantages for laboratory automation platforms and could transform how researchers design experiments involving fluid handling, chemical synthesis, and biological assays where power constraints and thermal management are critical concerns.