Optimization Of Interdigitated Electrode Through Finite Element Analysis For Juice Adulteration Detection

Abstract

Recently, interdigitated electrodes (IDEs) have been applied in various industries because they are easy to fabricate and low-cost. However, the optimal electrode geometry for maximizing sensitivity remains unclear, as conflicting reports exist on the effects of finger width, spacing, and thickness under varying operating conditions. Therefore, a simulation study was conducted using COMSOL Multiphysics 5.6 software to determine which IDE offers the best sensitivity. The IDEs operate with two parallel coplanar electrodes, with periodic repetition of the design (i.e., length, width, and electrode spacing) to generate a high signal and reduce the signal-to-noise ratio. Finite element analysis via COMSOL revealed that an optimized configuration featuring a smaller gap size (0.1 mm), a wider finger width (0.4 mm), and an electrode count of 8 yielded an ideal sensor design, achieving a peak electric field of 2582.52 V/m and a current density of 1.57×10¹⁰ A/m². Following the computational analysis, the optimized IDE sensor was physically fabricated. Experimental verification using this low-cost, screen-printed silver sensor successfully demonstrated a distinct contrast in electrical resistance; pure fruit juices exhibited a low baseline resistance between 2.5 and 6 ?, whereas commercialized variants reached significantly higher values of up to 35 ? over a 5-hour testing window. This strong correlation highlights the platform's stability and its immediate capacity to distinguish juice purity. These findings confirm that the optimized IDE platform provides a highly viable, inexpensive solution for detecting food and beverage adulteration.

ABSTRAK: Kebelakangan ini, elektrod berselang-seli (IDE) telah digunakan secara meluas dalam pelbagai industri kerana mudah difabrikasi dan berkos rendah. Walau bagaimanapun, geometri elektrod yang optimum bagi memaksimum kepekaan masih tidak jelas, kerana terdapat laporan bercanggah mengenai kesan lebar jari, jarak, dan ketebalan di bawah keadaan operasi berbeza. Oleh itu, satu kajian simulasi telah dijalankan menggunakan perisian COMSOL Multiphysics 5.6 bagi menentukan konfigurasi IDE berkepekaan terbaik. IDE beroperasi berdasarkan dua elektrod koplanar selari, dengan pengulangan berkala parameter reka bentuk iaitu panjang, lebar, dan jarak antara elektrod, bagi menjana isyarat tertinggi dan mengurangkan nisbah isyarat-ke-bunyi. Analisis unsur terhingga melalui COMSOL mendapati bahawa konfigurasi optimum dengan saiz jurang ebih kecil (0.1 mm), lebar jari lebih lebar (0.4 mm), dan bilangan elektrod sebanyak 8 telah menghasilkan reka bentuk sensor ideal, dengan mencapai medan elektrik puncak sebanyak 2582.52 V/m dan ketumpatan arus sebanyak 1.57×10¹? A/m². Selepas analisis pengiraan, sensor IDE yang dioptimumkan telah difabrikasi secara fizikal. Pengesahan eksperimen menggunakan sensor perak cetakan skrin berkos rendah ini berjaya menunjukkan perbezaan ketara dalam rintangan elektrik; jus buah-buahan tulen menunjukkan rintangan asas yang rendah antara 2.5 ? dan 6 ?, manakala varian komersial mencapai nilai yang lebih tinggi sehingga 35 ? dalam tempoh ujian selama 5 jam. Korelasi yang kuat ini menyerlahkan kestabilan platform dan keupayaannya yang segera bagi membezakan ketulenan jus. Penemuan ini mengesahkan bahawa platform IDE yang dioptimumkan menyediakan penyelesaian praktikal dan murah bagi mengesan pemalsuan makanan dan minuman.