미세가공 기술 기반의 마이크로니들 어레이 개발 및 패럴린 적용 가능성에 관한 연구

김동국,윤덕규,이용찬,김민욱,노지형,서요한,강관수,정영훈,김경아,송태하 대한의용생체공학회 2023 의공학회지 Vol.44 No.6

In this research, we studied the development of a SUS304 microneedle array based on microfabrication technology and the applicability of Parylene-C thin film, a medical polymer material. First of all, four materials com- monly used in the field of medical engineering (SUS304, Ti, PMMA, and PEEK) were selected and a 5 μm Parylene- C thin film was deposited. The applicability of Parylene-C coating to each material was confirmed through SEM anal- ysis, contact angle measurement, surface roughness(Ra) measurement, and adhesion test according to ASTM stan- dards for each specimen. Parylene-C thin film was deposited based on chemical vapor deposition (CVD), and a 5 μm Parylene-C deposition process was established through trial and error. Through characteristic experiments to confirm the applicability of Parylene-C, SUS304 material, which is the easiest to apply Parylene-C coating without pretreat- ment was selected to develop a microneedle array based on CNC micromachining technology. The CNC microma- chining process was divided into a total of 5 steps, and a microneedle array consisting of 19 needles with an inner diameter of 200 μm, an outer diameter of 400 μm, and a height of 1.4 mm was designed and manufactured. Finally, a 5 μm Parylene-C coated microneedle array was developed, which presented future research directions in the field of microneedle-based drug delivery systems.

방광외벽에 대한 영구적 생체이식장치의 코팅물질로서 Parylene-C의 생체적합성연구

이동섭,김수진,손동완,최범규,이문규,이승준,김세웅 대한남성과학회 2010 The World Journal of Men's Health Vol.28 No.3

Purpose: Development of an implantable bladder volume sensor that could reduce complications and improve the quality of life for neurogenic bladder patients is assignment task that falls in the field of urology. Nevertheless, there is lack of research on whether biomaterials are biocompatible to the urinary bladder or not. Polyethylene glycol (PEG), polydimethylsiloxane (PDMS) and parylene-C are well known biocompatible materials in other fields of medicine. Because PEG is biodegradable and PDMS has a relatively low affinity to substrate with less durability than parylene-C, we evaluated the biocompatibility of parylene-C to the urinary bladde,r comparing of it to PEG and PDMS. Materials and Methods: Nine rabbits were classified into three groups. Coin shaped aluminum substrates were affixed onto the external wall of the urinary bladder in each rabbit. At this point, the three rabbits which had substrates coated with PEG were assigned to group 1, those with PDMS were assigned to group 2 and those with parylene-C were assigned to group 3. In each group, one rabbit was sacrificed at one week, another rabbit was sacrificed at two weeks and the other rabbit was sacrificed at four weeks. At each time microscopic evaluation was done. To detect macrophages, we used fluorescence microscopy and applied MAC 387 staining. Results: At one week, macrophage accumulation was observed on the external surface of the urinary bladder adjacent to the device no matter which material was used as a coating, but it had almost disappeared by four weeks. In addition, the inflammatory reaction was limited at the external surface of the urinary bladder, and did not expand into the muscular layer. Conclusions: With respect to biocompatibility, there was no difference among the three biomaterials. With its characteristics of durability and easy affinity regardless of the type of substrate, parylene-C would make an excellent coating material for a bio-device implantable into the urinary bladder.

Parylene based bilayer flexible gate dielectric layer for top-gated organic field-effect transistors

Shin, E.Y.,Choi, E.Y.,Noh, Y.Y. ELSEVIER 2017 ORGANIC ELECTRONICS Vol.46 No.-

In this paper, we report on a bilayer insulating film based on parylene-c for gate dielectric layers in top-gate/bottom-contact inkjet-printed organic field-effect transistors (OFETs) with indacenodithiophene-co-benzothiadiazole (IDTBT) and poly([N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bitthiophene)) (P(NDI2OD-T2)) as with p- and n-channel semiconductors. The thin parylene-c film (t = 210 nm) show large gate leakage density (2.52 nA/cm<SUP>2</SUP> at 25 V) and low breakdown voltage (2.2 MV/cm). In addition, a degraded field-effect mobility (μ) was observed in printed IDTBT and P(NDI2OD-T2) OFETs with the parylene-c single-layered dielectric. X-ray photoelectron spectroscopy (XPS) analysis reveals that the degradation of μ is due to unwanted chemical interaction between parylene-c and the conjugated polymer surface during the parylene-c deposition process. By inserting 50-nm thick poly(methyl-methacrylate) (PMMA) and polystyrene (PS) layer in-between the parylene-c and conjugated polymer film, highly improved gate leakage density and breakdown voltage are achieved. The printed IDTBT and P(NDI2OD-T2) OFETs with a bilayer dielectric compose of parylene-c and PMMA and PS show significantly improved hole and electron μ of 0.47 cm<SUP>2</SUP>/Vs and 0.13 cm<SUP>2</SUP>/Vs, respectively, and better operation stability. In addition, we demonstrate inkjet-printed polymer complementary inverter with a high voltage gain of 25.7 by applying a PS/parylene-c bilayer dielectric.

On-Chip Parylene-C Microstencil for Simple-to-Use Patterning of Proteins and Cells on Polydimethylsiloxane

Lee, Donghee,Yang, Sung American Chemical Society 2013 ACS APPLIED MATERIALS & INTERFACES Vol.5 No.7

<P>Polydimethylsiloxane (PDMS) is widely used as a substrate in miniaturized devices, given its suitability for execution of biological and chemical assays. Here, we present a patterning approach for PDMS, which uses an on-chip Parylene-C microstencil to pattern proteins and cells. To implement the on-chip Parylene-C microstencil, we applied SiO<I>x</I>-like nanoparticle layers using atmospheric-pressure plasma-enhanced chemical vapor deposition (AP-PECVD) of tetraethyl orthosilicate (TEOS) mixed with oxygen. The complete removal of Parylene-C from PDMS following application of SiO<I>x</I>-like nanoparticle layers was demonstrated by various surface characterization analysis, including optical transparency, surface morphology, chemical composition, and peel-off force. Furthermore, the effects of the number of AP-PECVD treatments were investigated. Our approach overcomes the tendency of Parylene-C to peel off incompletely from PDMS, which has limited its use with PDMS to date. The on-chip Parylene-C microstencil approach that is based on this Parylene-C peel-off process on PDMS can pattern proteins with 2-μm resolution and cells at single-cell resolution with a vacancy ratio as small as 10%. This provides superior user-friendliness and a greater degree of geometrical freedom than previously described approaches that require meticulous care in handling of stencil. Thus, this patterning method could be applied in various research fields to pattern proteins or cells on the flexible PDMS substrate.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2013/aamick.2013.5.issue-7/am4001166/production/images/medium/am-2013-001166_0012.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/am4001166'>ACS Electronic Supporting Info</A></P>

Highly stable flexible organic field-effect transistors with Parylene-C gate dielectrics on a flexible substrate

Kwon, Hyeok-jin,Ye, Heqing,An, Tae Kyu,Hong, Jisu,Park, Chan Eon,Choi, Yongseon,Shin, Seongjun,Lee, Jihoon,Kim, Se Hyun,Li, Xinlin Elsevier 2019 Organic electronics Vol.75 No.-

<P><B>Abstract</B></P> <P>Poly(chloro-p-xylene), or Parylene-C, is a polymeric insulating material that has good physical and chemical properties, such as a high dielectric strength, a pin-free surface, and good mechanical/chemical stability, but is difficult to apply to top-contact-structured OFETs since its hydrophobic and very rough surfaces hinder the growth of organic semiconductor crystals and promote the formation of interface traps. Herein, we applied a blend of PS and TIPS-PEN dissolved in 1,2,3,4 tetrahydronaphthalene to overcome these limitations of Parylene-C. To confirm the influence of this system, we analyzed the morphologies of crystals grown on Parylene-C surfaces modified by various organic and polymer materials, including methacryloxypropyltrimethoxysilane, hexamethyldisilazane, and dimethylchlorosilane-terminated polystyrene. Our investigation showed the ability of the PS:TIPS-PEN blend system to be used to overcome the above-described limitations of Parylene-C, and to manufacture top-contact OFETs displaying stable operation under gate-bias stress. Notably, we applied Parylene-C and this blend system in practical flexible OFETs that displayed highly stable properties.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Parylene-C film fabricated by CVD methods is characterized as gate insulating materials. </LI> <LI> Bottom gate top contact OFETs on hard/flexible substrate fabricated with TIPS-PEN: PS blend system and CVD based Parylene-C are reported. </LI> <LI> Morphological structure of TIPS-PEN is investigated using the tools including CPOM, SEM, AFM and 2D-GIXD. </LI> <LI> The OFETs show the mobility of 0.32, and 0.21 cm<SUP>2</SUP>/V in hard and flexible device type with negligible hysteresis both case. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Parylene C‑AlN Multilayered Thin‑Film Passivation for Organic Light‑Emitting Diode Using a Single Deposition Chamber

Akpeko Gasonoo,Jeong‑Hwan Lee,Young‑Ji Lim,Seung‑Hun Lee,Yoonseuk Choi,Jae‑Hyun Lee 대한금속·재료학회 2020 ELECTRONIC MATERIALS LETTERS Vol.16 No.5

Poly-para-xylylene C (Parylene C) and Aluminium Nitride (AlN) multilayered thin films using a single chamber are proposedto achieve transparent passivation for organic light-emitting diodes (OLED). Parylene C-AlN multilayered thin filmswere obtained through a sequential deposition of Parylene C layers by an optimized chemical vapor deposition as well asdeposition of AlN layers by radio frequency reactive sputtering within a short process time at room temperature. An OLEDpassivated with the thin film showed a significant extension of shelf-life of 400 h at 25 °C and 30% RH without any formationof dark spots during the shelf-life analysis, while a reference OLED without any passivation film was degraded within24 h. In addition, the multilayered passivation films exhibited considerable optical transparency with transmittance greaterthan 85% in the visible range. This result demonstrates that Parylene C-AlN multilayered films can be successfully depositedwithin a short time at room temperature in a single chamber for passivation applications in transparent flexible OLEDs andother organic electronic devices.

Parylene-C 코팅된 의료용 SUS304 소재의 결합력 향상을 위한 플라즈마 처리 효과

김동국,송태하,정용훈,강관수,윤덕규,김민욱,우영재,서요한,김경아,노지형 한국표면공학회 2022 한국표면공학회지 Vol.55 No.6

Parylene-C which was mainly used for industries such as electronics, machinery and semiconductors has recently been in the spotlight in the medical field due to its properties such as corrosion resistance and biocompatibility. In this study we intend to derive a plan to improve the bonding strength of Parylene-C coating with the SUS304 base material for medical use which can be applied to various medical fields such as needles, micro needles and in vitro diagnostic device sensors. Through plasma pretreatment the bonding strength between Parylene-C and metal materials was improved. It was confirmed that the coated surface was hydrophobic by measuring the contact angle and the improvement of the surface roughness of the sample manufactured through CNC machining was confirmed by measuring the surface roughness with SEM. Through the above results, it is thought that it will be effective in increasing usability and reducing pain in patients by minimizing friction when inserting medical devices and in contact with skin. In addition it can be applied to various application fields such as human implantable stents and catheters, and is expected to improve the performance and lifespan of medical parts.

Investigation on Parylene-C based neural electrodes by accelerated life test and reliability improvement using polyimide flexible cable

Kim Ju-Hwan,Baek Dong-Hyun,Kim Dae Hwan,Park Dong-Wook 한국물리학회 2022 Current Applied Physics Vol.39 No.-

Since the encapsulation layer of the neural electrode plays an important role in determining the reliability of the device, more studies on the long-term reliability of Parylene-C are required. In this paper, we described the longterm reliability of Parylene-C based neural electrodes through an accelerated lift test and proposed a method to improve the reliability using polyimide flexible cable (PFC) attached to the Parylene-C device. The accelerated lifetime test was performed in phosphate-buffered saline at 50 ◦C. The electrochemical characteristics were acquired and analyzed to evaluate the reliability of the Parylene-C coated neural electrode for up to 56 days, which is equivalent to 115 days as an accelerated time. The proposed PFC method showed improved long-term stability of the device, demonstrating an increased lifetime, showing that testing conditions and device setup affect overall results. This study will help make reliable Parylene-C based neural electrode systems with improved moisture protection.

Inductively-Coupled Nitrous-Oxide Plasma Etching of Parylene-C Films

D. A. Shutov,강승열,백규하,서경수,권광호 한국물리학회 2009 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.55 No.5

In this article, we report results obtained from a study carried out on inductively-coupled plasma (ICP) etching of poly-monochloro-para-xylylene (parylene-C) thin films using N2O gas. The effects of the process parameters on the etch rate were investigated and are discussed in this work in terms of plasma parameter measurement performed using a Langmuir probe and modeling calculations. Process parameters of interest include the ICP source power and bias power. Oxygen atoms O(3P) were shown to be the major etching agent of polymer. At the same time, we propose that while positive ions are not an effective etchant, they play an important role as an effective channel of energy transfer from the plasma to the polymer. In this article, we report results obtained from a study carried out on inductively-coupled plasma (ICP) etching of poly-monochloro-para-xylylene (parylene-C) thin films using N2O gas. The effects of the process parameters on the etch rate were investigated and are discussed in this work in terms of plasma parameter measurement performed using a Langmuir probe and modeling calculations. Process parameters of interest include the ICP source power and bias power. Oxygen atoms O(3P) were shown to be the major etching agent of polymer. At the same time, we propose that while positive ions are not an effective etchant, they play an important role as an effective channel of energy transfer from the plasma to the polymer.

Development of Organic Thin-film Transistors on a Biocompatible Parylene-C Substrate

KyungMin Kim,Sookyeong Kim,Ah-Hyun Hong,Yoojeong Ko,Hyowon Jang,Hyeok Kim,Dong-Wook Park 대한전자공학회 2023 Journal of semiconductor technology and science Vol.23 No.1

Organic thin-film transistors (OTFTs) fabricated on a biocompatible Parylene-C substrate can be applied to biosensors using a simple and cost-effective process. In this study, we developed biocompatible OTFTs by using organic materials to fabricate the substrate, gate dielectric, channel, and passivation layer. Poly(3-hexylthiophene) (P3HT) was used to fabricate the OTFTs on a Parylene-C-based platform. As the gate dielectric, Parylene-C showed promising insulation properties. Finally, we generated a cyclic olefin polymer (COP) passivation layer to protect P3HT from oxygen and moisture, and the effect of the COP passivation layer on the P3HT channel was analyzed. The proposed materials and fabrication methods will be useful for various bio-applications of OTFTs.