目前眾多的光固化3D列印成型法大多面臨幾項問題(1)列印解析度(2)成型時間(3)單色或多色而非真正全彩。因此本研究採用PC-based控制開發出一套具漸層彩色光固化3D列印系統，並搭配反應速率快及機電轉換效率高等特性的壓電噴頭加強列印速度，系統包含軸向控制、噴頭控制、UV光控制、溫度控制與電壓波型控制等。
在解析度方面，採用兩排交錯、同排之間pitch為0.3387mm且共384孔的壓電式噴頭以提高解析度，若以雙排灌入不同顏色並噴印於單色原始解析度為75dpi，若以雙排灌入相同顏色並噴印於單色可使解析度提升至150dpi，除此之外本研究也採用次像素分割法，至少可使解析度提高至300dpi。
在列印控制方面，壓電噴頭主要透過平台上光學尺訊號觸發壓電噴頭噴出樹酯，並採用雙方向列印與偶數次像素分割以確保每次列印時兩排噴孔皆能噴墨。在彩色漸層方面，採用青色與洋紅色光固化樹酯進行初步雙色漸層噴印並以單層空間不重疊不空隙之方式噴印。除了以上幾點為3D彩色漸層重要因子外，電壓波型、溫度控制與bitmap圖檔處理方式皆為噴印品質重要關鍵。經實驗結果，本研究採用雙壓電噴頭建立之光固化彩色漸層3D列印技術，其解析度可達到150 dpi以上及雙色漸層顏色最少16階以上，相信彩色3D列印能在未來生活上有更多的應用產品。

Recently, most 3D printing machine with photo curable technique have some problems such as (1) resolution(2) printing time(3) mono-color or multi-color objects not full-color objects. The purpose of this study is to develop a photo-curable 3D printing mechatronics system with gradient color by using piezoelectric inkjet. The system includes motion control, piezo head control, UV light control, temperature control and waveform control.
In order to increase resolution, a piezo-head with 384 nozzles in two rows(the pitch in same row is 0.3387mm), is used in this study. The original resolution of 75 dpi (mono color) can be obtained by a piezo-head with one color each row. However, the resolution of 150 dpi (mono color) can be obtained by using one color only for each head. To achieve the higher resolution over 150 dpi, an AC servo motor (X axis) with position resolution of 0.5um is used to shift the piezo-head and carry out the sub-pixel printing work.
In terms of printing control, an optical linear scale on the stage is used as feedback signal to trig the piezo-head for proper printing work. A sub-pixel printing method is used to guarantee the print work on both even and odd row at the same time. In terms of gradient color, cyan resin and magenta resin are used to print with without overlap and free space on single layer in this study. Due to the significance of a complete layer during the additive manufacturing process, the system must control many parameters such as position, temperature, UV light and waveform and slicing image process etc. From the experimental results with two piezo-heads, the developed color 3D printing technique can achieve the resolution of 150 dpi and gradient ability of 16 levels between twin-colors. It may provide more applications with full-color 3D printing in the future.

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