Thermal management of a pico projector by using a multiple fans with a piezoelectric actuator system

In this study, multiple fans with a piezoelectric actuator (MFPA) system was adopted to transfer the heat inside a pico projector. Different MFPA models with different dimensional combinations of carbon fiber plates and Mylar plates were developed and their thermal performance along with resonant frequency and vibrating amplitude and power consumption were investigated. The result showed that the MFPA system with the combination of a 35 mm carbon fiber plate and a 5 mm Mylar plate had the best thermal performance with the thermal resistance of 4.93 W/m-K while the input power for the heater was 8 W and input voltage for the MFPA was 80 V. Meanwhile, the average vibrational amplitude reached 12.25 mm with the power consumption of 0.12 W at the resonant frequency of 61.5 Hz. To further enhance the cooling ability, this MFPA model was connected to the heat pipe module, and the efficiency of this model was compared to that of the rotary fan. The result revealed that the MFPA system on the heat pipe module achieved an amazing efficiency of 40.6% while that of the rotary fan was 47.3%, and the power consumption for the MFPA was 0.12 W which was merely 8.6% of 1.35 W for the rotary fan.