Description
Efficient thermal management in compact and sealed systems remains challenging due to the reliance on bulky mechanical pumps and the limited design flexibility of conventional cooling architectures. In this work, we present a pump-less ferrofluidic cooling approach that leverages electro-permanent magnet (EPM) actuation combined with 3D-printed fluidic channels to enable programmable and localized heat transport in confined environments. Additive manufacturing enables rapid prototyping of channels with varied geometries, including straight, serpentine, and branched configurations, providing a flexible platform to explore the coupling between channel topology, magnetic actuation parameters, and thermal behavior.
Magnetic fluid circulation is driven by externally placed EPM units that generate spatially and temporally controlled magnetic field gradients. By sequentially switching neighboring EPMs, a traveling-wave magnetic actuation scheme is formed, producing an effective magnetic pressure that drives ferrofluid flow through the printed channels without moving mechanical components. Compared to continuously driven electromagnetic coils, EPM-based actuation avoids sustained Joule heating by maintaining magnetic fields without continuous power input, making it particularly suitable for thermal management applications where actuator-induced heating must be minimized. This digital actuation strategy enables reversible flow direction, rapid on–off control, and waveform-tunable transport, while maintaining the magnetic field with negligible static power consumption.
A simplified coupled dynamic framework is introduced to relate EPM pulse timing and strength to magnetic body forces, flow resistance within the channels, and the resulting heat-transfer response. The framework supports parameter selection and experimental design by revealing key trends linking flow rate, thermal transport, and electrical energy input. A modular experimental platform incorporating localized resistive heating and temperature monitoring is established to evaluate flow controllability and cooling response across different channel geometries and actuation schemes.
This study establishes an integrated experimental and modeling framework for investigating magnetically driven ferrofluid transport for thermal management applications. Initial observations suggest that channel topology plays a critical role in balancing hydraulic resistance against magnetically induced driving forces. These results highlight fundamental design trade-offs between increasing heat-transfer surface area and maintaining achievable flow under pump-less magnetic actuation, pointing toward compact, low-power, and reconfigurable thermal management solutions for high-density electronic systems.