A Miniature Double Oscillating-Fan Cooling System Using Electromagnetic Force

In this study, an oscillating-fan cooling device using electromagnetic force has been proposed. The device consists of two oscillating-fans flapping back and forth. It requires only one electromagnet and two elastic blades with one magnet on each of them. The electromagnet and two elastic blades are situated on a base and arranged accordingly. And thus, the electromagnetic force generated by the electromagnet can actuate the blades. The main advantage of this cooling device compared to a rotary fan is its simple structure because there is no bearing and motor in the cooling device. Moreover, the simplicity of the device makes it a highly reliable and low cost cooling device. The driving current can be either DC PWM or AC under 8 V – 12 V so it is compatible to most electronic devices. The dimensions of the cooling device can be designed as small as 20 mm (L) * 30 mm (W) * 4 mm (H) and as large as 60 mm * 55 mm * 25 mm. For a cooling experiment, three cooling devices with the dimension of 50 mm * 50 mm * 15 mm were incorporated with a heat sink with the dimension of 190 mm * 110 mm * 15 m. The dummy heater dissipated 55W while the environmental temperature is 44.8 °C. The result showed that the dummy heater can be cooled from 120.7 °C to 69.3 °C while the total power consumption of the three cooling devices is 1.74 W. The result shows that the cooling device not only provides an outstanding cooling ability but also shows a great potential for structural reliability and design flexibility.