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Abstrak :
Teknik timbul panas berbiaya rendah untuk ilmu mikro dan nanoteknologi merupakan teknik menjajikan di bidang litografi konvensional yang menghasilkan replikasi pola atau motif yang berkualitas tinggi. Di studi ini, teknik tersebut diaplikasikan dengan polimer yang dipilih secara selektif dan terdiri dari cetakan (yang berfungsi sebagai stempel) dengan pola mikropilar 5 x 5µm dan material acuan (yang bertindak sebagai substrat penerima pola dari stempel). Polimer yang digunakan adalah polystyrene (PS) dan polydimethylsiloxane (PDMS). Studi ini sebagian besar ditujukan untuk mengeksplorasi dan menilai batas resolusi dari replikasi pola akhir menggunakan mesin timbul panas konvensional (WT90-DS) yang sesuai dengan kebutuhan laboratorium berbasis universitas. Proses timbul panas memiliki tiga parameter kunci: temperatur, waktu, dan tekanan. Proses timbul panas ini memiliki beberapa tahapan: pemanasan, penahanan, pendinginan, istirahat, dan pelepasan cetakan. Studi ini menunjukkan hasil yang menjajikan dengan menganalisis tinggi dan lebar dari pola yang tercetak yang dibandingkan dengan cetakan referensi menggunakan profilometry. Hasil menunjukkan bahwa temperatur 120 °C dan tekanan 4kg menghasilkan replikasi terbaik dengan menampilkan keseragaman tinggi dan lebar dari pola jika dibandingkan dengan pola referensi. ......Low-cost hot embossing techniques for micro and nanotechnology studies is a promising conventional lithography technique that produces high-quality replications of patterns. In this study, the technique used prudent selections of polymers and consists of mould (which acts as a stamp) with a micropillar pattern of 5 x 5µm and moulding (which acts as the substrate that receives patterns from the stamp). The polymers used are polystyrene (PS) and polydimethylsiloxane (PDMS). This study is mainly aimed to explore and assess the resolution limit of the final pattern replication employing conventional hot embossers (WT90-DS) that match the necessities of a university-based lab. The embossing process requires three key parameters: temperature, time, and pressure. This hot embossing process experiences several stages: heating, holding, cooling, resting, and demoulding. The study demonstrates promising results by analysing the imprinted pattern’s height and width compared with the mould dimensions as a reference by utilising profilometry. The result shows that the temperature of 120 °C with a pressure of 4kg produces the best result by displaying uniform height and width of pattern compared to the reference.

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ABSTRAK
Dalam pengembangan teknologi di dunia medis, pemantauan kesehatan secara konstan dan berkesinambungan yang dilakukan secara realtime merupakan salah satu parameter utama tercapainya keberhasilan dalam proses penyembuhan pasien.Namun hingga saat ini masih terdapat berbagai kendala seperti degradasi kualitastransfer pembacaan sinyal elektrik oleh elektroda konduktif hingga yang bersifat biologis seperti iritasi pada kulit jika dilakukan pemantauan jangka panjang. Salah satu solusi untuk mengatasi hal tersebut ialah dengan melakukan substitusi terhadap material bioelektroda Ag/AgCl yang telah digunakan secara konvensional dengan bioelektrodacampuran Polydimethylsiloxane (PDMS) dan Carbon Nanotube (CNT) yang memiliki tingkat fleksibilitas mekanik maupun parameter biodegradabilitas yanglebih baik. Pada penelitian ini telah dilakukan proses fabrikasi komposit PDMS dengan material filler penguat berupa Carbon Nanotube Berdinding Tunggal (SWCNT) dengan perbedaan variabel konsentrasi sebesar 3%, 5%, dan 7%. Didapatkan bahwa saat dilakukan proses karakterisasi mekanik modulus elastisitas (E) dari komposit dengan prosedur uji tarik mikro, besarnya peningkatan konsentrasi CNT berpengaruh pada nilai modulus, dengan rincian pada spesimen awal ialah sebesar 1,794 MPa dan mengalami peningkatan signifikan menjadi 3,149 MPa lalu tingkat kenaikannya melemah menjadi 3,27 MPa. Pemodelan analitik mikromekanik juga telah dilakukan mencakup pemodelan aturan pencampuran Voigt dan Reuss, hingga pemodelan Halpin-Tsai yang lebih kompleks

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ABSTRACT
The development in the medical technology area, a constant and continous health monitoring performed in real time is one of the main parameters to achieve success in the healing process of the patient. But until now there are still many obstacles such as the degradation of the quality of the reading transfer using electrical signals by conductive electrodes to the biological problem such as irritation to the skin if done on long-term monitoring. One solution to overcome this problem is to conduct the substitution of the bioelectrode material of Ag / AgCl which has been used conventionally with a novel bioelectrode, a mixture of Polydimethylsiloxane (PDMS) and Carbon Nano Tube (CNT) which has a better qualityin mechanical flexibility and biodegradability parameters. This study has been conducted with fabrication PDMS composite and its reinforcing filler material in the form of Single-Walled Carbon Nano Tube (SWCNT) with the difference of concentrations variable consist 3%, 5% and 7%. We report that when the process is carried out the mechanical characterization of the modulus of elasticity (E) of the composite with micro tensile test procedure, the amount of increase in the concentration of CNTs cause an effect on the value of modulus, with details on the first specimen is at 1.794 MPa and increased significantly to 3,149 MPa, then the rates of increase weakened to 3.27 MPa. Analytic modeling micromechanical modeling has also been covered include Voigt and Reuss model which known as aRules of Mixture, and more complex model such as Halpin-Tsai model

Abstrak :
Dalam studi ini, campuran Chlorinated Rubber (CR), Polydimethylsiloxane (PDMS) dan Grafena Oksida (GO) diteliti secara sistematis untuk diusulkan sebagai aditif anti-fouling dalam poliuretan (PU). Peningkatan kekuatan tarik diperoleh dengan penambahan campuran CR dan PDMS:GO. Spektrum Forier Transform Infra-red menunjukkan penurunan intensitas regangan ikatan rangkap C=C dan memunculkan ikatan Si pada senyawa kimia PU. Untuk mengetahui peran fungsi anti-fouling, sampel direndam di laut selama dua bulan. Selanjutnya sampel yang direndam di laut dikarakterisasi menggunakan mikroskop optik dan pengujian mekanik. Pengamatan mikroskop optik diperoleh bahwa penambahan CR mengurangi pertumbuhan teritip mikro dan penambahan PDMS:GO menurunkan pertumbuhan alga mikro. Untuk penelitian lebih lanjut, pengukuran Electrochemical Impedance Spectroscopy (EIS) dikembangkan untuk mengetahui spektrum impedansi sampel sebelum dan sesudah perendaman dalam air distilasi. Hal ini menunjukkan bahwa impedansi total berubah dengan perendaman. Elemen rangkaian ekivalen dari spektrum impedansi dimodelkan untuk mengekstrak resistansi seri, resistansi paralel, dan kapasitansi. Menariknya, resistansi seri, resistansi paralel dan kapasitansi berubah secara konsisten yang menunjukkan kemungkinan pelepasan elemen anti-fouling selama perendaman untuk setiap sampel. Selanjutnya dilakukan uji pelapukan di bawah sinar ultraviolet (UV) selama 500 jam untuk mengetahui kerusakan sifat mekanik. Hasil pengamatan menunjukkan bahwa pada awal paparan sinar UV hingga 80 jam kuat tarik meningkat signifikan. ......In this study, a mixed chlorinated rubber (CR), polydimethylsiloxane (PDMS) and graphene oxide (GO) was systematically investigated to propose as anti-fouling additives in polyurethane (PU). The increasing of tensile strength were observed by the addition of the mixture of CR and PDMS:GO. The Fourier transform infra-red spectra showed the decreasing of a C=C strain group and increasing Si bond of chemical compounds of PU, respectively. In order to investigate the role of the anti-fouling function, the samples were immersed in the sea for two months. Further the immersed samples in the sea were characterized using optical microscope and mechanical testing. The optical microscope observation obtained the addition of CR reduced the growth of micro barnacle and the addition of PDMS:GO decreased the growth of micro algae. To more elaboration, the electrochemical impedance spectroscopy (EIS) measurement was developed to investigate the impedance spectra of the samples before and after immersion in distilled water. It showed that the total impedance changed by the immersed samples. The equivalent circuit element from the impedance spectra was modelled to extract the series resistance, parallel resistance and capacitance. Interestingly, the series resistance, parallel resistance and capacitance were changed consistently which indicated the probably of the anti-fouling element release during the immersion for each sample. Furthermore, the ageing test under ultraviolet (UV) light was performed for 500 hours to investigate the decay of the mechanical properties. It was observed that the UV light ageing initially increased the tensile strength until of 80 hours exposure.

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Sebuah prototipe untuk Mesin PCR yang portabel, terjangkau, dan mudah digunakan telah dikembangkan oleh Universitas Indonesia untuk melakukan DNA Polymerase Chain Reaction (PCR). Studi ini membantu dalam pengembangan perangkat semacam itu agar menjadi Mesin PCR yang efektif dan reliable. Reliability perangkat semacam itu harus diukur dan dipahami untuk memastikan peforma yang optimal dan masa pakai yang tepat. Tujuan dari makalah ini adalah untuk secara khusus melihat sistem Thermal Cycler mesin, sistem di mana kemungkinan kegagalannya paling tinggi. Memahami karakteristik Thermal Cycler dapat membantu menghadirkan perangkat yang lebih baik secara keseluruhan, karena sistem ini menjadi garis keturunan dari keseluruhan proses PCR. Reliability sistem akan ditentukan melalui uji performa dan endurance di mana Thermal Cycler akan terus dipantau dan dianalisis untuk memberikan gambaran mengenai cara kerja perangkat ini, sehingga dapat di upgrade, didesain ulang, atau disiapkan langsung untuk penggunaan komersial. ......A prototype for a portable, affordable, and user-friendly PCR Machine has been developed by the University of Indonesia to perform DNA Polymerase Chain Reaction (PCR). This study helps in the development of such a device for it to become an effective and reliable PCR Machine. It is imperative that the reliability of such a device is measured and understood to ensure an optimal performance and lifetime. The goal of this paper is to specifically look at the Thermal Cycler system of the machine, the system in which the probability of failure is the highest. Understanding the characteristics of the Thermal Cycler may help bring a better overall device, as this system becomes the bloodline of the whole Polymerase Chain Reaction process. The reliability of the system will be determined through performance and endurance tests where the Thermal Cycler be constantly monitored and analyzed to paint a picture of working of this device, so that it may be upgraded, redesigned, or presented as is for commercial use.

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Ada banyak metode yang telah dikembangkan untuk menghasilkan mikrokapsul untuk keperluan enkapsulasi sel punca. Namun, emulsi mikrofluida ditemukan memuaskan karena memungkinkan kita untuk menghasilkan tetesan berukuran rata yang dapat dikontrol secara efisien, di mana bahkan memungkinkan untuk melakukan enkapsulasi sel tunggal di setiap tetesan. Namun proses ini bukan tanpa masalah, terlihat bahwa kapsul mikro mudah larut dalam larutan buffer salin Ca2+/Mg2+. Masalah menunjukkan bahwa kapsul memiliki kekuatan mekanik yang buruk dan tidak stabil. Oleh karena itu, enkapsulasi ganda diperlukan, yang memungkinkan untuk menambahkan lapisan lain ke kapsul yang akan memungkinkan stabilitas lebih baik dan meningkatkan kekuatan mekanik. Di sini, studi awal enkapsulasi lapisan ganda dilakukan dengan menggunakan teknologi Lab-On-Chip dan minyak serta air sebagai bahan pengujian. Studi ini mengeksplorasi penggunaan Chip Polycarbonate (PC) dan Polydimethylsiloxane (PDMS) untuk enkapsulasi lapisan ganda. Simulasi Computational Fluid Dynamics (CFD) awalnya dilakukan untuk memastikan bahwa laju aliran sesuai untuk pengujian chip dan kemudian chip diuji secara individual dan dikarakterisasi, di mana parameter yang sesuai untuk enkapsulasi lapisan ganda diperoleh dan digunakan untuk menghasilkan sistem enkapsulasi ganda. Hasilnya menunjukkan karakteristik generasi tetesan dari chip individu dan desain sistem dua chip yang sukses yang dapat menghasilkan enkapsulasi lapisan ganda dengan ukuran sekitar 1300 -1700μm. Studi banding juga mengkonfirmasi fenomena yang diamati. Tulisan ini dapat digunakan untuk riset lebih lanjut pada enkapsulasi dua lapis terkendali mengunakan Lab-on-Chip. ...... There had been many methods developed to generate microcapsules for stem cell encapsulation purposes. However, microfluidic emulsion is found to be satisfactory as it allows us to generate a controllable even sized droplets efficiently, where it is even possible to encapsulate single cell in each droplet. However, this process does not come without a problem, it was noticed that the micro capsules were easily dissolved in a saline buffer solution Ca2+/Mg2+. The issue shows that the capsules had poor mechanical strength and were unstable. Therefore, double encapsulation was introduced, which allows us to add another layer to the capsule with would allow more stability and increase mechanical strength. Here, an initial study of double layer encapsulation is conducted with Lab-On-Chip technology using oil and water as testing materials. This study explores the use of Polycarbonate (PC) and Polydimethylsiloxane (PDMS) Chip for double layer encapsulation. A Computational Fluid Dynamics (CFD) simulation was initially conducted to ensure that flowrates were suitable for chip testing and then the chips are tested individually and characterized, where suitable parameters for double layer encapsulation were obtained and used to generate a double encapsulation system. The result shows the droplet generation characteristics of individual chips and a successful two chip system design that could generate double layer encapsulations with sizes of approximately 1300 -1700μm. Comparative studies also confirmed observed phenomenon. This paper can be used for further studies in controllable double-layer encapsulation using Lab-on-Chip.

Abstrak :
Pada penelitian ini, modifikasi permukaan bunga mawar (Rosa x odorata) menjadi superhidrofobik telah berhasil dilakukan dengan metode coating menggunakan material coating Polydimethylsiloxane/Carnauba wax. Polydimethylsiloxane (PDMS) digunakan untuk menurunkan energi permukaan pada bunga mawar dan carnauba wax digunakan untuk memberikan kekasaran permukaan pada bunga mawar. Hasil modifikasi permukaan bunga mawar dengan proses coating dikarakterisasi menggunakan Spektroskopi ATR-FTIR, SEM-EDX, dan Spektrofotometer UV-Vis. Hasil karakterisasi berdasarkan spektra ATR-FTIR menunjukkan puncak spesifik PDMS pada bilangan gelombang 1017,08 cm-1 dan 1095,26 cm-1 yang mengindikasikan ikatan Si-O-Si. Pengujian sifat superhidrofobik dilakukan dengan pengukuran sudut kontak air pada permukaan bunga mawar yang menghasilkan sudut kontak air tertinggi sebesar 165.4o pada konsentrasi optimum 1% PDMS dengan 9 kali pelapisan. Uji stabilitas fisik menunjukkan bahwa bunga mawar yang telah dimodifikasi permukaannya memiliki kestabilan yang lebih baik dibandingkan dengan bunga mawar yang belum dimodifikasi permukaannya.

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In this research, the surface modification of rose flower (Rosa x odorata) to be superhydrophobic was successfully carried out through the coating method using a Polydimethylsiloxane/Carnauba wax coating material. Polydimethylsiloxane (PDMS) used as a material to lower surface energy in roses and carnauba wax used to provide surface roughness to roses. The results of surface modification of roses through the coating process and uncoated roses were characterized using FTIR Spectroscopy, SEM-EDX, and UV-Vis Spectrophotometer. The results of characterization based on ATR-FTIR spectra show PDMS specific peak at 1017,08 cm-1 and 1095,26 cm-1 indicating Si-O-Si bond. Superhydrophobicity was determined by measuring water contact angle on the surface of the rose flower. The highest contact angle was reached by coating the surface 9 times with 1% PDMS, which was determined as the optimum concentration. The physical stability test of roses showed that the surface of the modified roses was more stable than the roses that was not modified

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ABSTRAK
Latar Belakang: siler polidimetilsiloksan merupakan siler baru yang berpotensi menutup saluran akar lebih baik. Tujuan: membandingkan tingkat kerapatan pengisian di sepertiga apeks antara teknik kon tunggal (KT) dan downpackbackfill (DB) menggunakan siler polidimetilsiloksan. Metode: empat puluh gigi premolar bawah dibagi menjadi dua kelompok KT dan DB. Setelah pengisian saluran akar, sampel diinkubasi, dilapisi cat kuku, direndam dalam tinta India, lalu dibuat transparan dengan metode Robertson. Kebocoran di sepertiga apeks dievaluasi dengan mikroskop stereo. Hasil: skor kebocoran terendah (0-0,5 mm) dimiliki oleh kelompok KT dan skor kebocoran tertinggi (>1 mm) dimiliki oleh kelompok DB. Kesimpulan: teknik kon tunggal memberikan tingkat kerapatan yang lebih baik dibandingkan downpack-backfill, walaupun secara statistik perbedaan antar keduanya tidak signifikan. ABSTRACT
Background: polydimethylsiloxane sealer is a brand new sealer that potentially has a better sealing ability to the root canal. Aim: to compare the apical sealing ability in one third apex between single cone (SC) and downpack-backfill (DB) technique using polydimethylsiloxane sealer. Methods: fourty extracted human manibular premolars devided into two group, SC and DB. After obturated with polydimethylsiloxane sealer, samples were stored in incubator, coated with nail varnish, immersed in India ink, and then specimens were cleared using Robertson?s technique. The apical dye penetration was evaluated using a stereomicroscope. Result: the lowest leakage score (0-0,5 mm) was found in SC group and the highest score(>1 mm) in DB group. Summary: single cone technique exibited better sealing ability rather than downpack-backfill technique, although no statistical significant difference between this two techniques. ;Background: polydimethylsiloxane sealer is a brand new sealer that potentially has a better sealing ability to the root canal. Aim: to compare the apical sealing ability in one third apex between single cone (SC) and downpack-backfill (DB) technique using polydimethylsiloxane sealer. Methods: fourty extracted human manibular premolars devided into two group, SC and DB. After obturated with polydimethylsiloxane sealer, samples were stored in incubator, coated with nail varnish, immersed in India ink, and then specimens were cleared using Robertson?s technique. The apical dye penetration was evaluated using a stereomicroscope. Result: the lowest leakage score (0-0,5 mm) was found in SC group and the highest score(>1 mm) in DB group. Summary: single cone technique exibited better sealing ability rather than downpack-backfill technique, although no statistical significant difference between this two techniques. ;Background: polydimethylsiloxane sealer is a brand new sealer that potentially has a better sealing ability to the root canal. Aim: to compare the apical sealing ability in one third apex between single cone (SC) and downpack-backfill (DB) technique using polydimethylsiloxane sealer. Methods: fourty extracted human manibular premolars devided into two group, SC and DB. After obturated with polydimethylsiloxane sealer, samples were stored in incubator, coated with nail varnish, immersed in India ink, and then specimens were cleared using Robertson?s technique. The apical dye penetration was evaluated using a stereomicroscope. Result: the lowest leakage score (0-0,5 mm) was found in SC group and the highest score(>1 mm) in DB group. Summary: single cone technique exibited better sealing ability rather than downpack-backfill technique, although no statistical significant difference between this two techniques.

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ABSTRAK
Valves tipe aktuasi pneumatik telah berhasil digunakan dalam banyak aplikasi lab-on-chip karena biaya rendah dan teknik fabrikasi yang sederhana. Untuk membuat modul katup, penelitian ini menggabungkan beberapa teknik seperti additive manufacturing dan teknologi Computer Numerical Control (CNC) milling juga dengan teknik pembuatan polimer seperti Polydimethylsiloxane (PDMS) dan silikon. Di sini, kami memperkenalkan valves dengan aktuasi pneumatik yang tertutup pada keadaan normal dimana valves menggunakan Thermoplastic Polyurethane (TPU) film yang memiliki fungsi sebagai diafragma pada control chamber. Tingkat tekanan di control chamber dikendalikan oleh vacuum pump untuk menciptakan kondisi vakum dan membuka valves sehingga cairan dapat mengalir. Pada akhir penelitian kami, kami melakukan pengujian pada valves sehingga valves dengan aktuasi pneumatik dapat bekerja sesuai dengan yang kami inginkan.

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ABSTRACT
Pneumatic actuation type valves have been used successfully in many lab-on-chip applications because of their low cost and simple fabrication techniques. To fabricate valves module, it combine techniques like additive manufacturing and Computer Numerical Control (CNC) milling technology also with polymer fabrication such as Polydimethylsiloxane (PDMS) and silicon. Here, we introduce a normally closed pneumatic actuation valves which using Thermoplastic Polyurethane (TPU) film function as a diaphragm in control chamber. Pressure level in control chamber is controlled by vacuum pump to create vacuum condition and open valves so fluid can flow through. At the end of our study, we tested the valves so pneumatic actuation valves can perform as we desired.