銬型微電極為神經義肢的重要元件，通常將其銬於神經周圍，用於直接刺激運動神經元，或者用來量測神經電訊號。從文獻上得知，當神經所受壓力大於20 mmHg時，便會對神經內之血液微循環造成阻礙，而導致神經組織之受損或壞死。因此，本研究應用微機電系統技術，利用薄膜製程技術發展內植壓力感測器之銬型微電極，以量測神經所受之壓力及監測其健康情況。以現有之電極製程技術，以及相關製程參數，選擇以電容式壓力感測器，來與銬型微電極之薄膜製程整合。

本研究所製作之電容式壓力感測器，在先前研究中透過有限元素法之電腦模擬，得到最大靈敏度設計之電極大小為700 × 700μm2，介電層厚度為4μm，量測範圍為0~100mmHg，而其靈敏度為1.81×10-4 pF / mmHg‧pF。在製程方面，已完成內植壓力感測器之銬型微電極之製作。並且製作一電容感測電路與架設一校正系統，進行壓力感測器之校正。同時測試介電層材料之機械性質，探討介電層之楊氏係數與感測器靈敏度之關係。此外，更透過神經銬型電極壓力感測器，量測不同直徑之銬型電極對神經所產生之壓力。最後透過動物實驗，探討電容式壓力感測器在動物體內之可行性。

Cuff electrode is an important component of neural prostheses, and they are usually wrapped around the nerves to stimulate the motor fibers or to measure the electrical signals of sensory fibers. It is known that the highest endurable pressure of the peripheral nerves is only 20mmHg. For a pressure over the limit, the micro circulation in the nerve fascicles will be blocked, causing ischemia in nerve tissues. The goal of this study is to design and fabricate a micro pressure sensor by MEMS technology and to be integrated with the cuff electrodes for monitoring the wellbeing condition of the peripheral nerves.

The maximum sensitivity of pressure sensors was determined from the simulation of finite element method in the previous study. The dimension of one sensing electrode is 700 by 700 micro meters, the thickness of dielectric layer is 4 micro meters, the measure range is 0 to 100 mmHg, and the sensitivity is 1.81×10-4 pF / mmHg‧pF. The fabrication of cuff electrodes with embedded pressure sensors is completed. A capacitance conditioning circuit is found and a calibration system is set up to calibrate the pressure sensor. The mechanical property of the dielectric layer, PDMS, is also measured to discuss the relationship between Young’s modulus and the sensitivity. Beside, a nerve cuff electrode pressure sensor is used to measure the external pressure generated by the cuff electrode of different diameters. Finally, the feasibility of capacitive pressure sensor is tested through an animal experiment.

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