**2. Research Methods**

A device of piezo actuation jet (PAJ) consists of a circular piezoelectric sheet and acrylic (PMMA) plate, which was a completely new method of heat dispersion in the present paper. The powders of PMMA named ACRYREX ®® CM-207 with high smoothness, clear transparency, and high gloss were supplied by CHI MEI CORPORATION (Taiwan) in this study. This study investigated different design patterns, including layouts with differences in the piezoelectric sheet size, spacing, and area, with the different types of devices ultimately being used with a high-power LED (HI-LED) [37–42] to determine the best PAJ used when combining several PAJs in series. Connecting the PAJs in series increases the overall amount of wind and allows for the addition or subtraction of devices according to the area of the heat source to effectively control the volume of the device of the PAJ and achieve the optimal dissipation effect. The research procedure is shown in Figure 1a. The PAJ (piezo actuation jet) device, respectively, includes two strategies containing performance measurement and structural design.

(**b**) Performance measurement

**Figure 1.** Experimental procedure. (**a**) Research procedure; (**b**) Performance measurement.
