本研究以三種壓電材料結合軟性雙層板製程，開發出柔性的壓電陣列感測器，並搭配包含兩種共用感測電路的CMOS晶片，實現了壓電陣列感測系統。
研究選用PZT與P(VDF-TrFE)作為壓電材料，與軟性雙層板製程和網板印刷製程做結合，同時應用TSMC 0.35 μm CMOS製程設計出連續式、開關電容式兩種共用感測電路，提升系統整合度。陣列大小範圍為長寬3 cm，壓電單元大小為長寬2.76 mm到5 mm，陣列數目為四行四列共十六個壓電單元，區分為每八個一組，並以兩顆CMOS晶片做訊號的增益選擇、雜訊濾波、訊號讀取等，最後以MATLAB做訊號處理。經測試，系統能即時偵測人體脈搏、變頻應力和陣列圖形，並有效濾除低頻雜訊，展現出在陣列觸覺感測的可能性。
壓電材料的選用上，第一間公司為宏惠光電股份有限公司訂購Thorlabs公司之PA4FEW（PZT壓電模塊）；第二間公司為綠匯有限公司訂購Poly-K公司之Copolymer 80/20（P(VDF-TrFE)壓電薄膜）；第三間公司為寰辰科技股份有限公司（ELECERAM）之Navy Type IV（PZT壓電薄片）。
在脈搏量測方面，三種壓電材料皆量測出了脈搏訊號，並能根據脈搏的QRS波組推算出脈搏的跳動次數介在68次／每分鐘到85次／每分鐘。PA4FEW在晶片放大後的電壓值介在250 mV到275 mV，Copolymer 80/20在晶片放大後的電壓值介在25 mV到28 mV，Navy Type IV在晶片放大後的電壓值介在50 mV到56 mV。
在變頻量測方面，我們對三種壓電材料構成的壓電陣列感測系統做頻譜分析，並發現PA4FEW除了符合震動源頻率出現高峰以外，偶數與奇數倍頻上也出現共振頻，而Copolymer 80/20與Navy Type IV只在奇數倍頻上出現共振頻。頻寬方面，PA4FEW的線性區域約位在2000 Hz以內，Copolymer 80/20的線性區域約位在800 Hz以內，Navy Type IV的線性區域約位在30 kHz以內。
在陣列可行性方面，我們發現PA4FEW所構成的壓電單元之間，並不會對共用感測電路產稱訊號耦合，因此我們對其另外進行了陣列圖形感測，並成功感測出英文字母NTHU所形成的二維分布圖。
放大後感測度方面，PA4FEW有最佳的放大後感測度為8.04 μV/Pa、Navy Type IV有居中的放大後感測度為1.97 μV/Pa、Copolymer 80/20有最差的放大後感測度為1.34 μV/Pa。Allan偏差方面，Copolymer 80/20有最佳的Allan偏差為第10 sec的23 μV、Navy Type IV有居中的Allan偏差為第30 sec的45 μV、PA4FEW有最差的Allan偏差第60 sec的80 μV。解析度方面，PA4FEW有最佳的解析度為9.95 Pa、Copolymer 80/20有居中的解析度為17.17 Pa、Navy Type IV有最差的解析度為22.89 Pa。

This study combines three piezoelectric materials with a flexible double-layer board process to develop a flexible piezoelectric array sensor. The sensor system integrates with a CMOS chip featuring two types of shared sensing circuits to achieve a piezoelectric array sensing system.
PZT and P(VDF-TrFE) were chosen as the piezoelectric materials, combined with a flexible double-layer board process and screen-printing technology. Using the TSMC 0.35 μm CMOS process, two types of shared sensing circuits, Continuous and SC, were designed to enhance system integration. The array measures 3 cm in length and width, with individual piezoelectric units sized between 2.76 mm and 5 mm. The array consists of 16 piezoelectric units arranged in a 4x4 matrix, divided into two groups of eight units. Two CMOS chips are used for signal amplification, noise filtering, and signal reading, with MATLAB employed for signal processing. Testing demonstrated that the system can detect human pulse signals, variable-frequency stress, and array patterns in real time, effectively filtering low-frequency noise, and showcasing its potential for tactile sensing applications.
For piezoelectric material selection, PA4FEW (PZT piezoelectric module) was sourced from Thorlabs through Hung Hui Optoelectronics Co., Ltd.; Copolymer 80/20 (P(VDF-TrFE) piezoelectric film) was procured from Poly-K via Green Energy Co., Ltd.; and Navy Type IV (PZT piezoelectric sheet) was supplied by ELECERAM via Global Well Tech Co., Ltd.
In Pulse Measurement, all three piezoelectric materials successfully measured pulse signals, with QRS waveforms allowing pulse rates to be calculated between 63 and 85 beats per minute. After chip amplification, PA4FEW exhibited voltage values ranging from 250 mV to 275 mV, Copolymer 80/20 from 25 mV to 28 mV, and Navy Type IV from 50 mV to 56 mV.
In Variable Frequency Measurement, frequency spectrum analysis of the piezoelectric array sensing system revealed that PA4FEW exhibited resonance frequencies at the source vibration frequency and at both even and odd harmonics. In contrast, Copolymer 80/20 and Navy Type IV only displayed resonance at odd harmonics. In terms of bandwidth, PA4FEW's linear region extended up to approximately 2000 Hz, Copolymer 80/20 up to 800 Hz, and Navy Type IV up to 30 kHz.
In Array Feasibility Measurement, it was observed that piezoelectric units formed from PA4FEW did not induce signal coupling in the shared sensing circuits. Additional array pattern sensing successfully captured a two-dimensional distribution representing the English letters "NTHU."
In terms of amplified sensitivity, PA4FEW exhibits the best amplified sensitivity of 8.04 μV/Pa, Navy Type IV has a moderate amplified sensitivity of 1.34 μV/Pa, and Copolymer 80/20 shows the lowest amplified sensitivity at 1.97 μV/Pa. Regarding Allan deviation, Copolymer 80/20 achieves the best Allan deviation of 23 μV at the 10-second mark, Navy Type IV has a moderate Allan deviation of 45 μV at the 30-second mark, and PA4FEW demonstrates the worst Allan deviation of 80 μV at the 60-second mark. As for resolution, PA4FEW offers the best resolution at 9.95 Pa, Copolymer 80/20 has a moderate resolution of 17.17 Pa, and Navy Type IV displays the lowest resolution at 22.89 Pa.

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