Pengembangan Sensor Impedansi Berbasis Komposit MWCNT/PDMS Dengan Struktur Interdigital Electrode Sebagai Kandidat NPK Meter

Nanda, Yehosua Krisna Putra (2026) Pengembangan Sensor Impedansi Berbasis Komposit MWCNT/PDMS Dengan Struktur Interdigital Electrode Sebagai Kandidat NPK Meter. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Pertumbuhan dan produktivitas tanaman sangat dipengaruhi oleh ketersediaan unsur hara makro nitrogen (N), fosfor (P), dan kalium (K). Pada sistem hidroponik maupun penggunaan pupuk organik cair (POC), kandungan nutrisi dapat bervariasi sehingga diperlukan metode pengukuran yang cepat dan sederhana. Penelitian ini bertujuan mengembangkan dan mengkarakterisasi sensor impedansi berbasis komposit MWCNT/PDMS dengan struktur interdigital electrode (IDE) sebagai kandidat sensor untuk karakterisasi awal larutan representatif NPK. Larutan KCl, KNO3, dan Na3PO4 digunakan sebagai representatif kalium, nitrat, dan fosfat. Sensor difabrikasi menggunakan komposit MWCNT/PDMS 3 wt% melalui proses dispersi menggunakan THF, sonikasi, pengadukan, dan pencetakan langsung dengan metode molding. Karakterisasi dilakukan menggunakan LCR meter IVYTECH 106x pada rentang frekuensi 2-200 kHz. Hasil menunjukkan bahwa impedansi cenderung menurun seiring meningkatnya frekuensi dan konsentrasi, meskipun terdapat respons non-linear pada konsentrasi tinggi. Berdasarkan analisis linearitas, rentang kerja linear diperoleh sebesar 50-200 ppm untuk KCl dan KNO3, serta 10-50 ppm untuk Na3PO4.. Frekuensi optimal berdasarkan regresi linear diperoleh sebesar 5 kHz untuk KCl, 2.5 kHz untuk KNO3, dan 2 kHz untuk Na3PO4. Sensitivitas sensor masing-masing sebesar 0,058622 MΩ/ppm, 0,046018 MΩ/ppm, dan 0,23314 MΩ/ppm. Rata-rata error fitting model regresi linear masing-masing sebesar 0,253%, 0,346%, dan 0,304%, sedangkan rata-rata error validasi masing-masing sebesar 0,582%, 0,770%, dan 0,530%. Hasil tersebut menunjukkan bahwa sensor MWCNT/PDMS berbasis IDE berpotensi dikembangkan lebih lanjut sebagai kandidat sensor impedansi untuk karakterisasi larutan nutrisi terkait NPK.
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Plant growth and productivity are strongly influenced by the availability of macronutrients, namely nitrogen (N), phosphorus (P), and potassium (K). In hydroponic systems and the use of liquid organic fertilizer (LOF), nutrient content may vary, requiring a fast and simple measurement method. This study aims to develop and characterize an impedance sensor based on an MWCNT/PDMS composite with an interdigital electrode (IDE) structure as a candidate sensor for the initial characterization of representative NPK solutions. KCl, KNO3, and Na3PO4 solutions were used as representative solutions of potassium, nitrate, and phosphate, respectively. The sensor was fabricated using a 3 wt% MWCNT/PDMS composite through dispersion with THF, sonication, stirring, and direct patterning using the molding method. Characterization was performed using an IVYTECH 106x LCR meter over a frequency range of 2-200 kHz. The results showed that impedance tended to decrease with increasing frequency and concentration, although non-linear responses were observed at high concentrations. Based on the linearity analysis, the linear working ranges were obtained at 50-200 ppm for KCl and KNO3, and 10-50 ppm for Na3PO4. The optimal frequencies based on linear regression were 5 kHz for KCl, 2.5 kHz for KNO3, and 2 kHz for Na3PO4. The sensor sensitivities were 0.058622 MΩppm, 0.046018 MΩ/ppm, and 0.23314 MΩ/ppm, respectively. The average fitting errors of the linear regression model were 0.253%, 0.346%, and 0.304%, respectively, while the average validation errors were 0.582%, 0.770%, and 0.530%, respectively. These results indicate that the MWCNT/PDMS-based IDE sensor has the potential to be further developed as a candidate impedance sensor for the characterization of NPK-related nutrient solutions.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	MWCNT/PDMS, NPK, Sensor Impedansi, Interdigital Electrode, Regresi Linear ============================================================ MWCNT/PDMS, NPK, Impedance Sensor, Interdigital Electrode, Linear Regression
Subjects:	Q Science > QC Physics > QC100.5 Measuring instruments (General) Q Science > QC Physics > QC271.8.C3 Calibration Q Science > QC Physics > QC610.3 Electric conductivity
Divisions:	Faculty of Science and Data Analytics (SCIENTICS) > Physics > 45201-(S1) Undergraduate Thesis
Depositing User:	Yehosua Nanda Krisna Putra
Date Deposited:	30 Jul 2026 06:41
Last Modified:	30 Jul 2026 06:41
URI:	http://repository.its.ac.id/id/eprint/139792

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