- 學位論文
具倒鉤微針乾式電極陣列之研製及其於腦波量測的應用
Development of Barbed Dry Electrode Arrays and Application for Electroencephalography
摘要
本研究提出一低成本之矽濕蝕刻製程，製作具有倒鉤之微針乾式電極陣列，並用於腦電波之量測。有別於以往傳統濕式電極，使用乾式電極量測腦電波時，不需進行皮膚處理或塗抹導電膠，增加量測之便利性。製程技術是以矽濕蝕刻為基礎，先以氫氧化鉀非等向性濕蝕刻製作初步金字塔型電極，再利用氫氟酸/硝酸等向性濕蝕刻製作倒鉤結構，並在電極上製作矽通孔，增加電極組裝後之導電性。其中，電極倒鉤曲率半徑與蝕刻時間成線性遞減關係。本研究使用之倒鉤電極平均長度為155 μm，底部寬度為86 μm。後端組裝方面，是使用移除導電膠後的心電波濕式電極貼片，再使用銀膠將乾式電極固定於鈕扣電極部分，即完成後端組裝。拉力量測結果顯示，倒鉤電極與軟性材料及皮膚之附著力會高於無倒鉤之電極。在電極-皮膚接觸阻抗量測方面，具有矽通孔之倒鉤電極較一般之倒鉤電極阻抗低；使用心電波濕式電極貼片組裝之倒鉤乾式電極，其阻抗會低於將導線一端使用銀膠固定在背面之乾式電極；具倒鉤之乾式電極，其接觸阻抗會略高於無倒鉤之乾式電極；將面積校正後之濕式電極接觸阻抗與乾式電極比較，在頻率300 Hz以下時，其值會大於無倒鉤乾式電極之接觸阻抗，但小於有倒鉤之乾式電極；頻率300 Hz以上時，其值會小於有倒鉤及無倒鉤之乾式電極接觸阻抗。使用倒鉤乾式電極量測腦電波，其訊號波形與濕式電極相似，表示本研究之倒鉤乾式電極能應用於腦電波之量測。
並列摘要
In this work, barbed dry electrodes array for EEG measurement was designed and fabricated by using low-cost silicon wet etching techniques. Compared with traditional wet electrodes, the proposed dry electrodes can avoid skin preparation and electrolytic gel during measurement process. The preliminary pyramidal electrodes arrays were fabricated by KOH etching, and the barbed shapes were formed by HF/HNO3 etching. The radii of curvature of barbs decrease almost linearly as the etching time increases. Also, a through-silicon via (TSV), which improves the conductivity between the electrode lead and the tip array, was created on the substrate during the etching process. The average height of the dry electrodes is about 155 μm, and the average base width is 86 μm. By using conductive silver epoxy, the fabricated dry electrode was bonded with a traditional commercial ECG electrode, on which the electrolytic gel was removed. The detaching force measurement results showed that the barbed electrodes array was more adherent to soft materials than the pyramidal electrodes array. In the electrode-skin contact impedance measurement, the impedance of barbed dry electrodes is slightly higher than that of the wet electrodes. We also demonstrated that the proposed barbed dry electrodes can be used to measure the EEG signal effectively.