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Design and Manufacturing of CNT-Based Nanodevices for Optical Sensing Applications
Published in Iniewski Krzysztof, Integrated Microsystems, 2017
Ning Xi, King Wai Chiu Lai, Jiangbo Zhang, Carmen Kar Man Fung, Hongzhi Chen, T. J. Tarn
On the other hand, we tried to prevent the oxygen-doping effect on a dedoped SWCNT-based IR detector. We deposited another single SWCNT on a pair of heterogeneous electrodes. Similarly, this SWCNT-based IR detector was annealed at 400°C in a vacuum furnace for 1 h, and hence the oxygen molecules were removed. Then, we tried to package it by a layer of parylene C thin film with a thickness of 1 μm. Parylene C is used as an oxygen barrier of the fabricated device based on its barrier properties [87]. In Figure 18.18, it showed I–V characteristics of a CNT-based IR detector over different states of the processes. Before the thermal annealing process, curves 1–3 indicted the fluctuation and the unstable performance of the detector. After the thermal annealing process (Curve 4), the current of the detector increased significantly. Finally, the I–V characteristics of the detector became very stable after the parylene C packaging process. The signals were repeated over a couple of days. The results indicated a method to maintain, control, and prevent the oxygen doping of a CNT device. This method included two steps: (1) oxygen removal by the vacuum thermal annealing process and (2) oxygen prevention by parylene C packaging process.
Microfluidics in assisted reproduction technology: Towards automation of the in vitro fertilization laboratory
Published in David K. Gardner, Ariel Weissman, Colin M. Howles, Zeev Shoham, Textbook of Assisted Reproductive Techniques, 2017
The fabrication materials used in current microfluidic devices display unique properties that must also be addressed before implementation into IVF labs. Although these properties may be conducive for fabrication purposes, materials such as PDMS are absorptive and can alter media characteristics, including media flow and osmolarity, thereby impeding subsequent embryo development (46). Fortunately, surface modification to fabrication materials, including parylene coating or bonding with poly(ethylene glycol) methyl ether methacrylate (PEG-MA), may alleviate some of these concerns (47, 48).
Hollow Microneedles
Published in Boris Stoeber, Raja K Sivamani, Howard I. Maibach, Microneedling in Clinical Practice, 2020
Other approaches based on surface micromachining were developed by Brazzle et al. (5) and Takeuchi et al. (6), both forming needle structures around sacrificial photoresist. Brazzle et al. used electroforming of nickel to fabricate microneedles on sacrificial photoresist layers patterned on a silicon membrane. The microneedle structures were 2 mm long with an inner channel of approximately 30 µm in width and 20 µm in height, and outer dimensions of approximately 80 µm in width and 60 µm in height. Fabrication of polymer in-plane microneedle neural probes was demonstrated by Takeuchi et al. A flexible needle-like probe was formed by deposition of parylene beneath and on top of a sacrificial photoresist layer corresponding to the inner channel. The resulting probes were several millimeters long with 200-µm-wide inner channels. As the high flexibility of the parylene structure did not allow penetration into the tissue, the authors proposed filling the needle channels with polyethylene glycol (PEG) temporarily prior to tissue penetration, to improve its rigidity. Stupar and Pisano (7) formed similar parylene microneedles around sacrificial silicon. The outline of a microneedle structure was first patterned, in the in-plane direction, through a thin silicon wafer using DRIE. A thick parylene layer was then vapor-deposited as the structural layer. The sacrificial silicon was then etched using KOH to create the hollow parylene microneedles. By partially etching the silicon, stiffer microneedles were made containing parylene shafts and single-crystal silicon tips. The resulting microneedles were able to endure very large deflection angles of up to 180°. A 2.65-mm-long microneedle with a width of 240 μm and wall thickness of 20 μm was measured to have a bending stiffness of 63.5 N/m.
Design of the novel ThermoBrachy applicators enabling simultaneous interstitial hyperthermia and high dose rate brachytherapy
Published in International Journal of Hyperthermia, 2021
Ioannis Androulakis, Rob M. C. Mestrom, Miranda E. M. C. Christianen, Inger-Karine K. Kolkman-Deurloo, Gerard C. van Rhoon
In the novel TB applicator model (Figure 1(II)), two 30 μm thick and 20 mm long copper layers are deposited onto the outer layer of a 6 Fr HDR-BT flexible POM afterloading catheter (Elekta ProGuide 6 F sharp needle), with a spacing of 5 mm between the electrodes. The copper layers leave a 0.5 mm circumferential opening along the catheter axis, which serves as a wiring path. The copper electrodes are connected by a 50 μm copper wire to the distal side of the catheter, from where they can be connected to the source. A thin, 30 μm dielectric conformal coating layer (Parylene C) covers the outer applicator to ensure capacitive coupling rather than galvanic contact with the tissue and to ensure biocompatibility [40]. The inside of the catheter is not obstructed, leaving the original space for insertion of the HDR-BT source from the afterloader. Since the TB applicator is in direct contact with patient tissue, it is a single use sterilized device.
An update on: long-term outcomes of penile prostheses for the treatment of erectile dysfunction
Published in Expert Review of Medical Devices, 2019
Brian Dick, Peter Tsambarlis, Amit Reddy, Wayne JG Hellstrom
While many of these studies were taking place, Mentor (Irvine, CA, purchased by Coloplast [Minneapolis, MN] in 2005) released an enhanced model of the Mentor alpha 1, which had reinforced pump component. Wilson et al compared the original vs enhanced model and observed the 5- and 10-year mechanical survival rates to be 77% and 65% vs 94% and 89%, showcasing the improved durability of the enhanced model [4]. Enemchukwu et al performed a more recent analysis of a different device improvement—parylene-coated cylinders and found a similar result. This study reviewed the files of 55,013 patients who received an AMS 700CX or Ultrex device between 1997 and 2008 and found the 7-year mechanical survival rate of nonparylene vs parylene-coated devices to be 91.1% vs 94.1% [5] (Table 1).
Blink detection and magnetic force generation for correction of lagophthalmos, with specific regard to implant compatibility testing
Published in Orbit, 2022
Razek Georges Coussa, Nikita Lomis, Fares Antaki, Jason Samle, Kavita Patel, George Christodoulou, Satya Prakash, James Oestreicher, Bryan Arthurs
After the implantation of any material into the body, tissue cell integration-based processes compete with bacterial adhesion to the surface of the implanted device and promote undesired inflammatory and fibrotic reactions.25 In order to enhance the biocompatibility of the designed samarium–cobalt magnets, polymeric coating has been widely used to isolate the surface of the implanted device. In this context, the parylene (poly(p-xylylene)) polymer family has proved very effective as a protective coating as it offers exceptional biocompatibility, hydrophilicity, excellent mechanical properties, and stability in the body fluid.26–28