在這個研究中，我們提出了一種作為阻抗生物感測器的指叉電極（IDE）的最佳結構。以COMSOL Multiphysics的有限元素分析模擬軟體來計算調整電極的形狀(半圓、弧形和矩形電極) 和電極的幾何參數(電極之間的間距、手指的長度和寬度，以及手指的數量) 對感測器的影響，以增進感測器的靈敏度。模擬的結果指出在同樣的操作電壓和頻率下， 相較於弧形和半圓電極，矩形電極提供較多集中的、較大的電場強度和較大的阻抗大小。 根據電極的幾何參數，較小的電極可以產生較高與較多集中的電場強度。具有18支手指，手指間距為0.1毫米，手指寬度為0.1毫米，手指長度為3毫米，電極厚度為0.05毫米的IDE是最佳的設計，可產生最高的電場強度。優化的電極強度為900.61 V / m，電極的電容為1.38 pF。 在電化學阻抗頻譜(Electrochemical Impedance Spectroscopy, EIS)分析中, 包含在相同的操作電壓與頻率下，不同形狀的電極，含/不含蛋白質的PBS溶液的培養基。針對不同形狀繪制針對阻抗和相角的PBS穩態圖。可以看出，隨頻率的增加，阻抗值減小，相位角沿負方向增加。根據模擬結果，矩形電極的阻抗和相位高於含/不含蛋白質的弧形邊緣電極和半圓電極。與弧形邊緣和半圓電極相比，矩形在電極的表面上也具有較強的電場。較強的電場會導致較大的阻抗。因此，矩形電極具有更好的靈敏度。 ;In this study, we present a preliminary investigation of optimum structures of an interdigitated electrode (IDEs) as impedance biosensors. The COMSOL Multiphysics finite element simulation software was conducted to investigate the shape of electrode (semi-circular, curvy-edged and rectangular electrode) and the effect of varying the geometrical parameters of the electrodes (spacing between the electrodes, finger width and length, and number of fingers) on the sensor performance to improve the sensitivity of the sensor. The simulation result indicates that the rectangular electrode provides more concentric, higher electric field strength and higher impedance magnitude compared with the curvy-edged and semi-circular electrode at the samoperatingal voltage and frequency. Based on the electrode geometry parameters, a higher and more concentric electric field strength will be generated with smaller electrodes. The IDE with 18 fingers, 0.1 mm in finger spacing and 0.1 mm in finger width, 3 mm in finger length and 0.05 mm in electrode thickness is the optimum design, which generates the highest electric field strength. The optimized electrode electric field strength is 900.61 V/m and the capacitance of the electrode is 1.38 pF. In EIS analysis includes, different shapes of electrode with and without protein in the medium of PBS solution at the same operating voltage and frequency. The PBS stabilization graph for impedance and phase angle plotted against different shapes. It is observed that with increase of frequency the impedance value decreases and the phase angle increases in negative direction. Based on the simulation result, the rectangular electrode impedance and phase is higher than the curved edge electrode and semi-circular electrode with and without protein. The rectangular also have strong electric field on the surface of the electrode compared to the curvy edged and semi-circular electrodes. The stronger electric fields cause greater impedance magnitude. Therefore, the rectangular electrodes have better sensitivity.
