Optimization of Silver-PDMS and Gold-PDMS Surface Nanocomposite Fabrication Technologies Considering LSPR and SERS Applications

2020 ◽  
Author(s):  
Alexandra Borok ◽  
Zsanett Izsold ◽  
Shireen Zangana ◽  
Attila Bonyar
Keyword(s):  
Pdms Surface

scholarly journals Alcohol-based highly conductive polymer for conformal nanocoatings on hydrophobic surfaces toward a highly sensitive and stable pressure sensor

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jung Joon Lee ◽  
Srinivas Gandla ◽  
Byeongjae Lim ◽  
Sunju Kang ◽  
Sunyoung Kim ◽  
...  
Keyword(s):  
Pressure Sensor ◽  
Mechanical Stability ◽  
Exchange Process ◽  
Conductive Polymer ◽  
High Sensitivity ◽  
Fast Response ◽  
Pdms Surface ◽  
Practical Applications ◽  
Sensor Applications ◽  
Water Based

Abstract Conformal and ultrathin coating of highly conductive PEDOT:PSS on hydrophobic uneven surfaces is essential for resistive-based pressure sensor applications. For this purpose, a water-based poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) solution was successfully exchanged to an organic solvent-based PEDOT:PSS solution without any aggregation or reduction in conductivity using the ultrafiltration method. Among various solvents, the ethanol (EtOH) solvent-exchanged PEDOT:PSS solution exhibited a contact angle of 34.67°, which is much lower than the value of 96.94° for the water-based PEDOT:PSS solution. The optimized EtOH-based PEDOT:PSS solution exhibited conformal and uniform coating, with ultrathin nanocoated films obtained on a hydrophobic pyramid polydimethylsiloxane (PDMS) surface. The fabricated pressure sensor showed high performances, such as high sensitivity (−21 kPa−1 in the low pressure regime up to 100 Pa), mechanical stability (over 10,000 cycles without any failure or cracks) and a fast response time (90 ms). Finally, the proposed pressure sensor was successfully demonstrated as a human blood pulse rate sensor and a spatial pressure sensor array for practical applications. The solvent exchange process using ultrafiltration for these applications can be utilized as a universal technique for improving the coating property (wettability) of conducting polymers as well as various other materials.

scholarly journals Universal Plasma Jet for Droplet Manipulation on a PDMS Surface towards Wall-Less Scaffolds

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1321
Author(s):  
Cheng-Yun Peng ◽  
Chia-Hung Dylan Tsai
Keyword(s):  
Plasma Treatment ◽  
Treatment Time ◽  
Plasma Jet ◽  
Aging Effect ◽  
Droplet Generation ◽  
Magnetic Actuation ◽  
Pdms Surface ◽  
Polymeric Surface ◽  
Air Jet ◽  
Droplet Manipulation

Droplet manipulation is important in the fields of engineering, biology, chemistry, and medicine. Many techniques, such as electrowetting and magnetic actuation, have been developed for droplet manipulation. However, the fabrication of the manipulation platform often takes a long time and requires well-trained skills. Here we proposed a novel method that can directly generate and manipulate droplets on a polymeric surface using a universal plasma jet. One of its greatest advantages is that the jet can tremendously reduce the time for the platform fabrication while it can still perform stable droplet manipulation with controllable droplet size and motion. There are two steps for the proposed method. First, the universal plasma jet is set in plasma mode for modifying the manipulation path for droplets. Second, the jet is switched to air-jet mode for droplet generation and manipulation. The jetted air separates and pushes droplets along the plasma-treated path for droplet generation and manipulation. According to the experimental results, the size of the droplet can be controlled by the treatment time in the first step, i.e., a shorter treatment time of plasma results in a smaller size of the droplet, and vice versa. The largest and the smallest sizes of the generated droplets in the results are about 6 µL and 0.1 µL, respectively. Infrared spectra of absorption on the PDMS surfaces with and without the plasma treatment are investigated by Fourier-transform infrared spectroscopy. Tests of generating and mixing two droplets on a PDMS surface are successfully achieved. The aging effect of plasma treatment for the proposed method is also discussed. The proposed method provides a simple, fast, and low-cost way to generate and manipulate droplets on a polymeric surface. The method is expected to be applied to droplet-based cell culture by manipulating droplets encapsulating living cells and towards wall-less scaffolds on a polymeric surface.

scholarly journals Self-restoring polymer brushes under tribological stress and the biomedical applications

MRS Advances ◽  
2016 ◽  
Vol 1 (27) ◽  
pp. 1971-1976
Author(s):  
Troels Røn ◽  
Irakli Javakhishvili ◽  
Søren Hvilsted ◽  
Katja Jankova ◽  
Seunghwan Lee
Keyword(s):  
Polymer Brushes ◽  
Diblock Copolymers ◽  
Polymer Chains ◽  
Aqueous Environment ◽  
Pdms Film ◽  
Pdms Surface ◽  
Tribological Application ◽  
Optimal Functions ◽  
Amphiphilic Diblock Copolymers

ABSTRACTFor biological and mechanical systems involving moving parts, surface slipperiness is often a critical attribute for their optimal functions. Surface grafting with hydrophilic polymers is a powerful means to render materials slippery in aqueous environment. In “inverted grafting-to approach”, the hydrophilic polymer chains of amphiphilic diblock copolymers dispersed within a poly(dimethylsiloxane) (PDMS) network are selectively segregated upon exposure to aqueous solution. This allows formation of extremely stable brush-like polymer layers. Tribological application of inverted grafting-to approach was successfully demonstrated with PDMS-block-poly(acrylic acid) (PDMS-b-PAA) dispersed within thin PDMS films on PDMS blocks by showing friction coefficients (µ) of ca 10-2 to 10-3, depending on the load, pH and buffer salinity in the absence of other external re-supply of PAA chains. Further manipulations of the thin PDMS film incorporating PDMS-b-PAA to optimize the tribological properties are presented. Lastly, first trials to employ PAA-grafted PDMS surface to generate in-vitro mucosae model are also presented and discussed.

Biomimetic antifouling PDMS surface developed via well-defined polymer brushes for cardiovascular applications

2018 ◽  
Vol 106 ◽  
pp. 305-317 ◽  
Author(s):  
Hakimeh Ghaleh ◽  
Kiyumars Jalili ◽  
Behnaz Memar Maher ◽  
Reza Rahbarghazi ◽  
Morteza Mehrjoo ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Pdms Surface

scholarly journals Novel Flexible Triboelectric Nanogenerator based on Metallized Porous PDMS and Parylene C

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1625 ◽  
Author(s):  
Massimo Mariello ◽  
Elisa Scarpa ◽  
Luciana Algieri ◽  
Francesco Guido ◽  
Vincenzo Mariano Mastronardi ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Power Density ◽  
Open Circuit ◽  
Triboelectric Nanogenerator ◽  
Steam Curing ◽  
Density Peak ◽  
Peak Voltage ◽  
Parylene C ◽  
Pdms Surface ◽  
Wide Range

Triboelectric nanogenerators (TENGs) have recently become a powerful technology for energy harvesting and self-powered sensor networks. One of their main advantages is the possibility to employ a wide range of materials, especially for fabricating inexpensive and easy-to-use devices. This paper reports the fabrication and preliminary characterization of a novel flexible triboelectric nanogenerator which could be employed for driving future low power consumption wearable devices. The proposed TENG is a single-electrode device operating in contact-separation mode for applications in low-frequency energy harvesting from intermittent tapping loads involving the human body, such as finger or hand tapping. The novelty of the device lies in the choice of materials: it is based on a combination of a polysiloxane elastomer and a poly (para-xylylene). In particular, the TENG is composed, sequentially, of a poly (dimethylsiloxane) (PDMS) substrate which was made porous and rough with a steam-curing step; then, a metallization layer with titanium and gold, deposited on the PDMS surface with an optimal substrate–electrode adhesion. Finally, the metallized structure was coated with a thin film of parylene C serving as friction layer. This material provides excellent conformability and high charge-retaining capability, playing a crucial role in the triboelectric process; it also makes the device suitable for employment in harsh, wet environments owing to its inertness and barrier properties. Preliminary performance tests were conducted by measuring the open-circuit voltage and power density under finger tapping (~2 N) at ~5 Hz. The device exhibited a peak-to-peak voltage of 1.6 V and power density peak of 2.24 mW/m2 at ~0.4 MΩ. The proposed TENG demonstrated ease of process, simplicity, cost-effectiveness, and flexibility.

Surface Treated PDMS by UV-Vis Light for Microfluidic Device

2008 ◽  
Vol 1139 ◽  
Author(s):  
Seisuke Kano ◽  
Sohei Matsumoto ◽  
Naoki Ichikawa
Keyword(s):  
Surface Treatment ◽  
Water Injection ◽  
Atmospheric Condition ◽  
Aluminum Foil ◽  
The Other ◽  
Wave Number ◽  
Treatment Technique ◽  
Hydrophobic Property ◽  
Flow Rates ◽  
Pdms Surface

AbstractHydrophobic property of PDMS surface was improved by the 400 W UV-Vis lamp light irradiation in the atmospheric condition for several ten minutes. As a result of this surface treatment, the surface became to hydrophilic character for one month long. This surface treatment technique applied to PDMS micro-fluidic device and verified valve-less switching. The UV-Vis light irradiated to PDMS micro fluidic pattern with partly covered by aluminum foil. Finally inlet and outlets were connected 0.5 mm diameter tubes. The syringe pumps injected the distilled water into the inlet of the PDMS micro channel at the flow rates of 0.5, 5.0, and 50 μl/min for the both width channel. As results of water injection water flowed only the UV-Vis treated channel at the flow rates of 0.5 and 5.0 μl/min. On the other hand, the water flowed for all channels at the flow rate of 50 μl/min. This result was observed from 5.0 μl/min flow again for both width devices which dried by air. These results were occurred by the difference of the flow conductance and wettability. The mechanism of this hyrophilicity of PDMS was reported to form Si-O in the surface by means of glassy surface. From the IR spectra, the Si-O-Si peak shifted to higher wave number for UV-Vis irradiated PDMS than the untreated PDMS comparing with the other IR peaks. This result showed that the Si-O-Si network bonding of PDMS changed to the O-Si-O bonding around the surface.

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