Electronic Theses and Dissertation

Ketersediaan perangkat analisis biosampel yang portabel dan handal telah menjadi bahan kajian yang menarik dalam bidang rekayasa perangkat biomedis. dalam penelitian ini, sebuah perangkat lab on chip dengan susunan mikroelektroda oblique dan v-shaped 2d dan 3d dalam mikrokanal telah dikembangkan untuk memanipulasi biopartikel menggunakan metode dielektroforesis (dep). mikroelektroda difabrikasi menggunakan kombinasi film tembaga dan indium tin oksida, sedangkan mikrokanal dibangun menggunakan isolator double tape. distribusi medan listrik tidak seragam pada mikroelektroda disimulasi dengan software quickfield 6.6 student version. sampel uji lactobacillus casei disiapkan dalam medium deionized water dan dekstrosa dengan konduktivitas listrik 0,05 s/m dan sampel sel darah merah disiapkan dalam medium deionized water dan edta dengan konduktivitas listrik 1,5 s/m. pengujian karakteristik dielektroforesis terhadap biopartikel yaitu lactobacillus casei dan sel darah merah dilakukan dengan mengaplikasikan sinyal ac sinusoidal pada mikroelektroda dan fenomena diamati menggunakan mikroskop dengan kamera charge-couple device (ccd). hasil simulasi menunjukkan pada susunan mikroelektroda oblique dan v-shaped 2d dan 3d terjadi gradien medan listrik dimana ada intensitas medan listrik lemah dan kuat. hasil pengujian karakteristik dep lactobacillus casei pada susunan mikroelektroda oblique 2d memperlihatkan bahwa hasil fenomena dep negatif teramati pada frekuensi 60-130 khz di daerah spasi ujung elektroda, sedangkan dep positif teramati pada frekuensi 380-700 khz di daerah spasi antar elektroda, semuanya pada tegangan 2-6 vpp. hasil pengujian karakteristik dep sel darah merah pada susunan mikroelektroda oblique dan v-shaped 3d menunjukkan fenomena dep negatif teramati pada frekuensi 5-7 mhz, 3,5-5 mhz, dan 2-4 mhz di daerah spasi elektroda oblique dan di daerah tengah lengkungan elektroda v-shaped. sedangkan fenomena dep positif teramati pada frekuensi 8-14 mhz, 6-13 mhz, dan 5-11 mhz di daerah tepi elektroda oblique dan di daerah ujung dalam lengkungan elektroda v-shaped, masing-masing berturut-turut pada penerapan tegangan 5 vpp, 10 vpp, dan 15 vpp. hasil penelitian ini memperlihat potensi yang menjanjikan dari perangkat lab on chip dengan susunan mikroelektroda oblique dan v-shaped untuk memanipulasi biopartikel sehingga biosampel dapat dianalisis lebih lanjut. kata kunci: lab on chip, mikroelektroda oblique dan v-shaped, dielektroforesis, lactobacillus casei, sel darah merah, medan listrik tidak seragam

The availability of portable and reliable biosample analysis devices has become an interesting topic of research in the field of biomedical device engineering. In this research, a lab on chip device with 2D and 3D oblique and V-shaped microelectrode arrays in a microchannel has been developed to manipulate bioparticles using the dielectrophoresis (DEP) method. The microelectrodes were fabricated using a combination of copper and indium tin oxide film, while the microchannel was constructed using a double tape insulator. The non-uniform electric field distribution on the microelectrodes was simulated using Quickfield 6.6 student version software. Lactobacillus casei test samples were prepared in deionized water and dextrose medium with an electrical conductivity of 0.05 S/m and red blood cell samples were prepared in deionized water and EDTA medium with an electrical conductivity of 1.5 S/m. Testing of dielectrophoresis characteristics of bioparticles, namely Lactobacillus casei and red blood cells, was carried out by applying a sinusoidal AC signal to the microelectrode, and the phenomenon was observed using a microscope with a charge-couple device (CCD) camera. The simulation results show that on the 2D and 3D oblique and V-shaped microelectrode arrays, the electric field gradient occurred, where there are weak and strong electric field intensities. The results of testing the DEP characteristics of Lactobacillus casei on a 2D oblique microelectrode arrays showed that the nDEP phenomena were observed at a frequency of 60-130 kHz in the electrode tip spacing area, while pDEP was observed at a frequency of 380-700 kHz in the spacing area between the electrodes, whole at a voltage of 2-6 Vpp. The results of testing the DEP characteristics of red blood cells on the oblique and V-shaped 3D microelectrode arrays showed that nDEP phenomena were observed at frequencies of 5-7 MHz, 3.5-5 MHz, and 2-4 MHz in the oblique electrode spacing area and in the center of the arch V-shaped electrode. Meanwhile, the pDEP phenomena were observed at frequencies of 8-14 MHz, 6-13 MHz, and 5-11 MHz in the edge area of the oblique electrode and in the inner tip area in the arch of the v-shaped electrode, respectively when applying a voltage of 5 Vpp, 10 Vpp, and 15 Vpp. The results of this research show the promising potential of a lab on chip device containing an oblique and v-shaped microelectrode array for manipulating bioparticles so that biosamples can be further analyzed. Keywords: Lab on chip, Oblique and V-shaped microelectrodes, Dielectrophoresis, Lactobacillus casei, Red blood cells, Non-uniform electric field