An Electromagnet-Based Magnetically-Activated Thermal Switch Without Moving Parts

TL;DR

This paper introduces a compact, electromagnet-based magnetically-activated thermal switch that operates without moving parts, enhancing thermal management efficiency for electronic devices by utilizing superparamagnetic nanofluids.

Contribution

The study presents a novel, fully automated MATS design using an electromagnet and nanofluid, eliminating the need for mechanical movement and improving heat transfer control.

Findings

Maximum temperature variation of 44.4°C at highest gradient

Fastest temperature change rate of 0.6°C/sec at highest gradient

Increased coil power improves heat exchange efficiency

Abstract

With the ever increasing power dissipation in electrical devices, new thermal management solutions are in high demand to maintain an optimal operating temperature and efficient performance. In particular, recently developed magnetically-activated thermal switches (MATSs) provide an alternative to existing devices, using the magnetic and thermal properties of superparamagnetic nanofluids to dissipate heat in a controlled manner. However, the presence of moving parts is a major drawback in those systems that must still be addressed. Herein, we present a compact and automatized MATS composed by an encapsulated superparamagnetic nanofluid and an electromagnet allowing to activate the MATS without any moving part. We investigate the effect of different temperature gradients (40, 26 and 10 C) and powers applied to the coil (6.5, 15, 25 and 39 W) on the performance of this novel MATS. The results show that the highest (44.4$) and fastest (0.6 C/s) temperature variation occur for the highest studied temperature gradient. On the other hand, with increasing power, there is also an increase in the efficiency of the heat exchange process between the two surfaces. These results remove one of the main barriers preventing the actual application of magnetic thermal switches and opens new venues for the design of efficient thermal management devices.