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 Spatially resolved spectroscopy of an atmospheric pressure microwave plasma jet used for surface treatment

2014 ◽  
Vol 13 (1) ◽  
Author(s):  
Lucia Potočňáková ◽  
Jaroslav Hnilica ◽  
Vít Kudrle
Keyword(s):  
Surface Treatment ◽  
Plasma Treatment ◽  
Microwave Plasma ◽  
Sessile Drop ◽  
Treatment Time ◽  
Optical Emission ◽  
Plasma Jet ◽  
Contact Angles ◽  
Individual Species ◽  
Optimal Position

AbstractIn this study, the variations of properties of a microwave plasma jet (surfatron) along the discharge axis have been investigated using optical emission spectroscopy. As the argon jet is not enclosed, the spatial distribution of individual species in effluent plasma is the result of rather complicated interplay between energy loss and gradual mixing with the air. Spatial 2D relative intensity profiles of atomic lines and molecular bands at 310 nm, 336 nm, 391 nm and 656 nm are presented in the form of colour maps revealing different positions of maximum emission intensity for 310 nm and 336 nm (in the effluent plasma) and for 391 nm and 656 nm (inside the discharge tube). The plasma jet was used for surface treatment of heat resistant samples (stainless steel, aluminium, silicon wafer) and the effectiveness of the plasma treatment was evaluated by measuring the sessile drop contact angle, with water and glycerol as testing liquids. The optimal position for plasma treatment (close to the tube nozzle) combined with longer treatment time (10 s) lead to hydrophilic properties of samples with contact angles as low as 10°.

scholarly journals Colour Fading of Textile Fabric by Plasma Treatment

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
H. F. Cheung ◽  
C. W. Kan ◽  
C. W. M. Yuen ◽  
J. Yip ◽  
M. C. Law
Keyword(s):  
Plasma Treatment ◽  
Atmospheric Pressure ◽  
Treatment Condition ◽  
Treatment Time ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Reactive Dye ◽  
Reactive Blue 19 ◽  
Fading Effect ◽  
Textile Fabric

Colour fading of a reactive dye (C.I. Reactive Blue 19) dyed textile fabric was performed by atmospheric pressure plasma (APP) treatment with the use of plasma jet. Under the APP treatment condition of treatment time = 5 sec/mm; ignition power = 160 W; oxygen concentration = 1%; jet distance = 3 mm, significant colour-fading effect was achieved. For comparison purpose, the reactive dye dyed textile fabric was subjected to conventional enzymatic colour-fading process. Experimental results revealed that the APP-induced colour-fading effect was comparable with conventional enzymatic colour-fading process.

FABRICATION OF TWO-DIMENSIONAL PHOTONIC CRYSTALS WITH GE2SB2TE5 NANOHOLE ARRAYS BY NANOSPHERE LITHOGRAPHY

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1300-1305
Author(s):  
KI-HO SONG ◽  
HYUN-YONG LEE ◽  
HOE-YOUNG YANG ◽  
SUNG-WON KIM ◽  
JAE-HEE SEO ◽  
...  
Keyword(s):  
Photonic Crystals ◽  
Plasma Treatment ◽  
Treatment Time ◽  
Reduction Rate ◽  
Nanosphere Lithography ◽  
Two Dimensional ◽  
Photonic Bandgaps ◽  
Nanohole Arrays ◽  
Plasma Treatment Time ◽  
Lift Off

Two-dimensional photonic crystals (2D-PCs) with Ge 2 Sb 2 Te 5 ( GST ) nanohole arrays were prepared by the nanosphere lithography (NSL) process. A primary factor of PCs is that the refractive index (n) and the n-modulation can be realized by using the GST films, which exhibit a reversible phase transformation between amorphous and crystalline states by laser illumination. The polystyrene (PS) spheres with a diameter of 500 nm were spin-coated on Si substrate and subsequently reduced by O 2-plasma treatment. The reduced spheres were utilized as a lift-off mask of the NSL process and their size and separation could be precisely controlled. Amorphous GST films were thermally evaporated and then the reduced PS spheres were removed. The fabricated GST nanohole arrays were observed by SEM and AFM. The nanohole diameters are nearly linearly reduced with increasing plasma-treatment time (t). The reduction rate (δ) for the conditions of this work was evaluated to be ~ 0.92 nm/s. The period (Λ) and filling factor (η) of PCs are structure parameters that determine their photonic bandgaps (PBGs). η-modulation can be easily achieved via a control of t and the Λ can be also modulated by the use of PS spheres with specific diameter. In addition, the PBGs for the fabricated GST 2 D PC were calculated by considering the amorphous and crystalline states of GST .

Submicron surface roughening of aliphatic polyamide 6,6 fabric through low temperature plasma and its effect on interfacial bonding in rubber composite

2017 ◽  
Vol 47 (8) ◽  
pp. 2029-2049 ◽  
Author(s):  
Siddhan Periyasamy ◽  
Krishna Prasad G ◽  
Raja ASM ◽  
Prashant G Patil
Keyword(s):  
Surface Roughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Plasma Treatment ◽  
Treatment Time ◽  
Surface Roughening ◽  
Temperature Plasma ◽  
Nylon 6,6 ◽  
Rubber Composite ◽  
Scanning Electron

The present study aims to produce submicron surface roughening of aliphatic polyamide 6,6 (nylon 6,6) fabric using dielectric barrier discharge-based atmospheric low temperature plasma for improving the adhesion bonding with rubber. The plasma treatment was done in the time ranging from 15 s to 300 s. Formation of surface roughness on the fabric due to plasma treatment and the associated chemical changes were studied through high-resolution scanning electron microscope, geometrical surface roughness by Kawabata evaluation system surface tester, contact angle measurements and Fourier transform infrared in Attenuated total reflectance mode. Scanning electron microscope micrographs revealed the presence of submicron roughness on the nylon 6,6 fibre surface with pores of around 100 nm (0.1 µm) for the optimum treatment time of 180 s above which the pore merging effect dominated resulting in the net low surface roughness. Geometrical roughness (SMD) results were also well in agreement with the scanning electron microscope results for the roughening and the optimum effect of the plasma treatment. The control and plasma treated nylon 6,6 samples were used as reinforcements for rubber composite. The peel strength of the rubber composite, which is a measure of interfacial bonding, increased to 150% as the maximum for the optimum plasma treatment time of 180 s. Intense rubber deposits over the 180 s plasma treated samples were observed while only a few deposits of rubber were observed on the control fabric when their interfaces were examined through scanning electron microscope after peeling test.

Surface Properties of UHMWPE Fiber after Low Temperature Argon-Plasma Treatment

2012 ◽  
Vol 499 ◽  
pp. 90-94 ◽  
Author(s):  
Jin Yun Xu ◽  
Wen Yu Wang ◽  
Xin Jin
Keyword(s):  
Molecular Weight ◽  
Low Temperature ◽  
Plasma Treatment ◽  
Treatment Time ◽  
Argon Plasma ◽  
Uhmwpe Fiber ◽  
Wetting Ability ◽  
Plasma Treatment Time ◽  
Uhmwpe Fibers ◽  
Ultra High Molecular Weight

To improve the adhesion between ultra-high-molecular-weight polyethylene (UHMWPE) fibers and matrix, the UHMWPE fibers were treated by low temperature argon-plasma. The effects of argon-plasma treatment on the properties of UHMWPE have been investigated. The roughness and wetting ability were all found to increase significantly after modifications. The tensile strength of UHMWE fibers were decreased with the plasma treatment time. The optimum plasma treatment is 2min.The increasing of roughness and wetting ability of UHMWPE fiber are beneficial to the improvement the adhesion between UHMWPE fiber and matrix.

scholarly journals Heterogeneous Bonding of PMMA and Double-Sided Polished Silicon Wafers through H2O Plasma Treatment for Microfluidic Devices

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 580
Author(s):  
Chao-Ching Chiang ◽  
Philip Nathaniel Immanuel ◽  
Yi-Hsiung Chiu ◽  
Song-Jeng Huang
Keyword(s):  
Plasma Treatment ◽  
Flow Rate ◽  
Gas Flow ◽  
Treatment Time ◽  
Optical Emission ◽  
Microfluidic Devices ◽  
Oh Radicals ◽  
Gas Flow Rate ◽  
Oh Groups ◽  
Plasma Treatment Time

In this work we report on a rapid, easy-to-operate, lossless, room temperature heterogeneous H2O plasma treatment process for the bonding of poly(methyl methacrylate) (PMMA) and double-sided polished (DSP) silicon substrates by for utilization in sandwich structured microfluidic devices. The heterogeneous bonding of the sandwich structure produced by the H2O plasma is analyzed, and the effect of heterogeneous bonding of free radicals and high charge electrons (e−) in the formed plasma which causes a passivation phenomenon during the bonding process investigated. The PMMA and silicon surface treatments were performed at a constant radio frequency (RF) power and H2O flow rate. Changing plasma treatment time and powers for both processes were investigated during the experiments. The gas flow rate was controlled to cause ionization of plasma and the dissociation of water vapor from hydrogen (H) atoms and hydroxyl (OH) bonds, as confirmed by optical emission spectroscopy (OES). The OES results show the relative intensity peaks emitted by the OH radicals, H and oxygen (O). The free energy is proportional to the plasma treatment power and gas flow rate with H bonds forming between the adsorbed H2O and OH groups. The gas density generated saturated bonds at the interface, and the discharge energy that strengthened the OH-e− bonds. This method provides an ideal heterogeneous bonding technique which can be used to manufacture new types of microfluidic devices.

Thermal plasma treatment of stormwater detention pond sludge

2008 ◽  
Vol 80 (9) ◽  
pp. 1993-2002 ◽  
Author(s):  
Jen-Shih Chang ◽  
Helena O. L. Li ◽  
Yiping Guo
Keyword(s):  
Plasma Treatment ◽  
Flow Rate ◽  
Thermal Plasma ◽  
Treatment Time ◽  
Air Flow ◽  
Sediment Quality ◽  
Air Flow Rate ◽  
Element Analysis ◽  
Weight Percentage ◽  
Detention Pond

A thermal plasma treatment experiment was conducted on stormwater detention pond sludge. The original sludge compositions were analyzed by neutron activation multi-element analysis. Thirty-two elements were detected in the sludge samples, and nine of them were below detection limit. The assessment of Zn, As, Mn, and Fe concentrations against the Ontario Ministry of Environment's Sediment Quality Guidelines indicated a marginal-to-significant pollution, and the concentration of Cr presented a gross pollution. After thermal plasma treatment, the mean weight percentage removal at 0 and 2 L/min of air flow rates was 2.78 ± 0.51 and 3.85 ± 1.35 %, respectively. The maximum weight removal of 5.87 % was achieved with 2 L/min air flow rate and 2 h of treatment time. Reduction of total organic carbon (TOC) increased with increasing treatment time and air flow rate. Eight gas compounds, CO, CO2, NO, NO2, NOx, SO2, H2S, and CxHy were measured and observed during the treatment process.

scholarly journals Polyimide Surface Modification Using He-H2O Atmospheric Pressure Plasma Jet-Discharge Power Effect

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 662
Author(s):  
Essam Abdel–Fattah ◽  
Mazen Alshaer
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Plasma Treatment ◽  
Atmospheric Pressure ◽  
Atmospheric Pressure Plasma ◽  
Plasma Jet ◽  
Discharge Power ◽  
Force Microscopy ◽  
Before And After ◽  
Power Effect

The atmospheric pressure He- H 2 O plasma jet has been analyzed and its effects on the Kapton polyimide surface have been investigated in terms of discharge power effect. The polyimide surfaces before and after plasma treatment were characterized using atomic force microscopy (AFM), X-ray photoelectrons spectroscopy (XPS) and contact angle. The results showed that, increasing the discharge power induces remarkable changes on the emission intensity, rotational and vibrational temperatures of He- H 2 O plasma jet. At the low discharge power ≤5.2 W, the contact angle analysis of the polyimide surface remarkably decrease owing to the abundant hydrophilic polar C=O and N–C=O groups as well as increase of surface roughness. Yet, plasma treatment at high discharge power ≥5.2 W results in a slight decrease of the surface wettability together with a reduction in the surface roughness and polar groups concentrations.

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