EXPERIMENTAL STUDIES OF SURFACE-DRIVEN CAPILLARY FLOW IN PMMA MICROFLUIDIC DEVICES PREPARED BY DIRECT BONDING TECHNIQUE AND PASSIVE SEPARATION OF MICROPARTICLES IN MICROFLUIDIC LABORATORY-ON-A-CHIP SYSTEMS

2015 ◽  
Vol 22 (04) ◽  
pp. 1550050 ◽  
Author(s):  
SUBHADEEP MUKHOPADHYAY ◽  
J. P. BANERJEE ◽  
ASHISH MATHUR ◽  
M. TWEEDIE ◽  
J. A. MCLAUGHLIN ◽  
...  

Proper bonding technique is investigated to achieve leakage-free surface-driven capillary flow in polymethylmethacrylate (PMMA) microfluidic devices. SU-8-based silicon stamp is fabricated by maskless lithography. This stamp is used to produce PMMA microchannel structure by hot embossing lithography. A direct bonding technique is mainly employed for leakage-free sealing inside PMMA microfluidic devices. The effect of surface wettability on surface-driven capillary flow is also investigated in PMMA microfluidic devices. The separation of polystyrene microparticles in PMMA laboratory-on-a-chip systems is investigated with the reduction of separation time by air dielectric barrier discharge (DBD) plasma processing of channel surfaces. This study is useful to fabricate the microfluidic laboratory-on-a-chip systems and to understand the surface-driven capillary flow.

2016 ◽  
Vol 52 (73) ◽  
pp. 10988-10991 ◽  
Author(s):  
Shaobo Li ◽  
Zhaofeng Wang ◽  
Hanmei Jiang ◽  
Limei Zhang ◽  
Jingzheng Ren ◽  
...  

In this work, we presented a novel route to synthesize boron doped reduced graphene oxide (rGO) by using the dielectric barrier discharge (DBD) plasma technology under ambient conditions.


Plasma ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Yingying Li ◽  
Rida Atif ◽  
Ketao Chen ◽  
Jiushan Cheng ◽  
Qiang Chen ◽  
...  

Dielectric barrier discharge (DBD) plasma has been found to uniquely polymerize ribose that is not usually subject to polymerization since molecules that tend to polymerize almost always possess at least a π-bond. The polymer was analyzed via nuclear magnetic resonance (NMR) spectra, matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectroscopy and Fourier-Transform inferred spectroscopy (FTIR), and it was found that dehydration occurs during polymerization.


Author(s):  
Yi Chen ◽  
Li Fei ◽  
Liming He ◽  
Lei Zhang ◽  
Chunchang Zhu ◽  
...  

A test platform was developed to investigate the performance of aero-engine combustor by the dielectric barrier discharge (DBD) plasma assisted combustion (PAC) in the simulated maximum condition. Conventional combustion experiments and plasma-assisted combustion conditions were conducted to study the effect of PAC on the performances including average outlet temperature, combustion efficiency and pattern factor under four different excessive air coefficients five different voltages. The comparative experiment shows that the combustion efficiency is improved after PAC compared with the normal conditions, the combustion efficiency of PAC increases 2.31% in the fuel-rich condition when Up-p is 40 kV. The uniformity of the outlet temperature field is also improved after PAC, the decrease of the pattern factor is more than 5% in the fuel-rich condition. These results offer certain reference value for the future application of PAC in aero-engine combustor and improving its performance.


2019 ◽  
Vol 36 (2) ◽  
pp. 157-173
Author(s):  
David E. Ashpis ◽  
Douglas R. Thurman

Abstract We address requirements for laboratory testing of AC Dielectric Barrier Discharge (AC-DBD) plasma actuators for active flow control in aviation gas turbine engines. The actuator performance depends on the gas discharge properties, which, in turn, depend on the pressure and temperature. It is technically challenging to simultaneously set test-chamber pressure and temperature to the flight conditions. We propose that the AC-DBD actuator performance depends mainly on the gas density, when considering ambient conditions effects. This enables greatly simplified testing at room temperature with only chamber pressure needing to be set to match the density at flight conditions. For turbine engines, we first constructed generic models of four engine thrust-classes; 300-, 150-, 50-passenger, and military fighter, and then calculated the densities along the engine at sea-level takeoff and altitude cruise conditions. The range of chamber pressures that covers all potential applications was found to be from 3 to 1256 kPa (0.03 to 12.4 atm), depending on engine-class, flight altitude, and actuator placement in the engine. The engine models are non-proprietary and can be used as reference data for evaluation requirements of other actuator types and for other purposes. We also provided examples for air vehicles applications up to 19,812 m (65,000 ft).


2018 ◽  
Vol 140 (10) ◽  
Author(s):  
F. F. Rodrigues ◽  
J. C. Pascoa ◽  
M. Trancossi

Dielectric barrier discharge (DBD) plasma actuators have several applications within the field of active flow control. Separation control, wake control, aircraft noise reduction, modification of velocity fluctuations, or boundary layer control are just some examples of their applications. They present several attractive features such as their simple construction, very low mass, fast response, low power consumption, and robustness. Besides their aerodynamic applications, these devices have also possible applications within the field of heat transfer, for example film cooling applications or ice formation prevention. However, due to the extremely high electric fields in the plasma region and consequent impossibility of applying classic intrusive techniques, there is a relative lack of information about DBDs thermal characteristics. In an attempt to overcome this scenario, this work describes the thermal behavior of DBD plasma actuators under different flow conditions. Infra-red thermography measurements were performed in order to obtain the temperature distribution of the dielectric layer and also of the exposed electrode. During this work, we analyzed DBD plasma actuators with different dielectric thicknesses and also with different dielectric materials, whose thermal behavior is reported for the first time. The results allowed to conclude that the temperature distribution is not influenced by the dielectric thickness, but it changes when the actuator operates under an external flow. We also verified that, although in quiescent conditions the exposed electrode temperature is higher than the plasma region temperature, the main heat energy dissipation occurs in the dielectric, more specifically in the plasma formation region.


Sign in / Sign up

Export Citation Format

Share Document