On-chip electrochemical detection of bio/chemical molecule by nanostructures fabricated in a microfluidic channel

2013 ◽  
Vol 177 ◽  
pp. 472-477 ◽  
Author(s):  
Kwi Nam Han ◽  
Cheng Ai Li ◽  
Minh-Phuong Ngoc Bui ◽  
Xuan-Hung Pham ◽  
Bum Sung Kim ◽  
...  
Keyword(s):  
Electrochemical Detection ◽  
Microfluidic Channel ◽  
On Chip

scholarly journals Design Methodology of Passive In-Line Relays for Molecular Communication in Flow-Induced Microfluidic Channel

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 65
Author(s):  
Puneet Manocha ◽  
Gitanjali Chandwani
Keyword(s):  
Communication System ◽  
Communication Systems ◽  
Microfluidic Channel ◽  
Microfluidic Channels ◽  
Molecular Communication ◽  
External Energy ◽  
Lab On Chip ◽  
Molecular Communication Systems ◽  
Macro Scale ◽  
On Chip

Molecular communication is a bioinspired communication that enables macro-scale, micro-scale and nano-scale devices to communicate with each other. The molecular communication system is prone to severe signal attenuation, dispersion and delay, which leads to performance degradation as the distance between two communicating devices increases. To mitigate these challenges, relays are used to establish reliable communication in microfluidic channels. Relay assisted molecular communication systems can also enable interconnection among various entities of the lab-on-chip for sharing information. Various relaying schemes have been proposed for reliable molecular communication systems, most of which lack practical feasibility. Thus, it is essential to design and develop relays that can be practically incorporated into the microfluidic channel. This paper presents a novel design of passive in-line relay for molecular communication system that can be easily embedded in the microfluidic channel and operate without external energy. Results show that geometric modification in the microfluidic channel can act as a relay and restore the degraded signal up-to 28%.

Microfluidic Channel Fabrication With Tailored Wall Roughness

2012 ◽  
Author(s):  
Jing Ren ◽  
Sriram Sundararajan
Keyword(s):  
Flow Behavior ◽  
Surface Texturing ◽  
Microfluidic Channel ◽  
Dip Coating ◽  
Etch Depth ◽  
Wall Roughness ◽  
Random Surface ◽  
Lab On Chip ◽  
On Chip ◽  
Autocorrelation Length

Realistic random roughness of channel surfaces is known to affect the fluid flow behavior in microscale fluidic devices. This has relevance particularly for applications involving non-Newtonian fluids, such as biomedical lab-on-chip devices. In this study, a surface texturing process was developed and integrated into microfluidic channel fabrication. The process combines colloidal masking and Reactive Ion Etching (RIE) for generating random surfaces with desired roughness parameters on the micro/nanoscale. The surface texturing process was shown to be able to tailor the random surface roughness on quartz. A Large range of particle coverage (around 6% to 67%) was achieved using dip coating and drop casting methods using a polystyrene colloidal solution. A relation between the amplitude roughness, autocorrelation length, etch depth and particle coverage of the processed surface was built. Experimental results agreed reasonably well with model predictions. The processed substrate was further incorporated into microchannel fabrication. Final device with designed wall roughness was tested and proved a satisfying sealing performance.

On-Chip Fabrication of None-Dead-Volume Microtips for ESI-MS Applications

2007 ◽  
Vol 121-123 ◽  
pp. 611-614
Author(s):  
Che Hsin Lin ◽  
Jen Taie Shiea ◽  
Yen Lieng Lin
Keyword(s):  
Surface Tension ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Dead Volume ◽  
Esi Ms ◽  
Rapid Fabrication ◽  
Chip Fabrication ◽  
Novel Method ◽  
On Chip ◽  
Highly Uniform

This paper proposes a novel method to on-chip fabricate a none-dead-volume microtip for ESI-MS applications. The microfluidic chip and ESI tip are fabricated in low-cost plastic based materials using a simple and rapid fabrication process. A constant-speed-pulling method is developed to fabricate the ESI tip by pulling mixed PMMA glue using a 30-μm stainless wire through the pre-formed microfluidic channel. The equilibrium of surface tension of PMMA glue will result in a sharp tip after curing. A highly uniform micro-tip can be formed directly at the outlet of the microfluidic channel with minimum dead-volume zone. Detection of caffeine, myoglobin, lysozyme and cytochrome C biosamples confirms the microchip device can be used for high resolution ESI-MS applications.

On-chip electrochemical detection of CdS quantum dots using normal and multiple recycling flow through modes

Lab on a Chip ◽  
2012 ◽  
Vol 12 (11) ◽  
pp. 2000 ◽  
Author(s):  
Mariana Medina-Sánchez ◽  
Sandrine Miserere ◽  
Sergio Marín ◽  
Gemma Aragay ◽  
Arben Merkoçi
Keyword(s):  
Quantum Dots ◽  
Electrochemical Detection ◽  
Cds Quantum Dots ◽  
Flow Through ◽  
On Chip ◽  
Multiple Recycling

Stable Microstructured Network for Protein Patterning on a Plastic Microfluidic Channel:  Strategy and Characterization of On-Chip Enzyme Microreactors

2004 ◽  
Vol 76 (21) ◽  
pp. 6426-6433 ◽  
Author(s):  
Haiyun Qu ◽  
Haitao Wang ◽  
Yi Huang ◽  
Wei Zhong ◽  
Haojie Lu ◽  
...  
Keyword(s):  
Microfluidic Channel ◽  
Protein Patterning ◽  
Channel Strategy ◽  
On Chip

scholarly journals Pneumatically Actuated Thin Glass Microlens for On-Chip Multi-Magnification Observations

Actuators ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 73
Author(s):  
Yusufu Aishan ◽  
Yaxiaer Yalikun ◽  
Yo Tanaka
Keyword(s):  
Optical System ◽  
Microfluidic Channel ◽  
Air Pressure ◽  
Resolving Power ◽  
Pdms Layer ◽  
Thin Glass ◽  
Firm Structure ◽  
Glass Slides ◽  
On Chip ◽  
Working Distance

This paper presents a self-contained micro-optical system that is magnification-controlled by adjusting the positions of the microlens in the device via pneumatic air pressure. Unlike conventional dynamic microlenses made from a liquid or polydimethylsiloxane (PDMS) that change their shapes via external actuation, this system combines a fixed-curvature glass microlens, an inflatable PDMS layer, and the external pneumatic air pressure supply as an actuator. This device showed several advantages, including stable inflation, firm structure, and light weight; it achieved a larger displacement using the glass microlens structure than has been reported before. This fixed-curvature microlens was made from 120 µm-thick flat thin glass slides, and the system magnification was manipulated by the deflection of a 100 µm-thick PDMS layer to alter the distance from the microlens to the microfluidic channel. The system magnification power was proportional to the air pressure applied to the device, and with a 2.5 mbar air pressure supply, a 2.2X magnification was achieved. This optical system is ideal for combining with high resolving power microscopy for various short working distance observation tasks, and it is especially beneficial for various chip-based analyses.

A Capillary Electrophoresis Platform With “On-Chip” Electrochemical Detection: Experimental and Computational Flow Studies

2001 ◽  
Author(s):  
Thomas J. Roussel ◽  
Robert S. Keynton ◽  
Kevin M. Walsh ◽  
Mark M. Crain ◽  
John F. Naber ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Electrochemical Detection ◽  
Power Supply ◽  
Electroosmotic Flow ◽  
Plug Flow ◽  
Finite Element Models ◽  
Separation Channel ◽  
Flow Models ◽  
On Chip ◽  
Electrochemical Potentials

Abstract The purpose of this study was to compare experimental electrokinetic plug flow velocities to computational flow models of microfabricated capillaries. Electroosmotic flow studies of dichlorofluorescein and electrophoretic separation of dopamine and catechol in a microfabricated capillary electrophoresis (CE) system were performed both experimentally and computationally. A “balanced cross design” consisting of a bent 2 cm long injection channel and a straight 2 cm long separation channel was used. The geometry of the capillary was 65 μm wide and 20 μm deep. For the fluorescein study, separation voltages ranging between 0.25 kV and 1 kV were applied, while voltages ranging from 100 V to 550 V were used in the separation studies. Laser Induced Fluorescent (LIF) images were obtained for flow visualization and qualitative analysis in the electroosmotic flow studies, while electrochemical potentials were acquired using “on-chip” electrodes interfaced to a custom-designed power supply and electrochemical detection (ECD) circuit. Finite element models of the experimental device were generated and flows were simulated using commercially available software. For the electroosmotic flow studies, the computational results were found to be within ± 11% of the experimentally obtained values. Similarly, the results of the computational separations of catechol and dopamine predicted plug velocities that were within ± 7.6% of the experimentally determined values.

On–Chip Droplets Sensing using Capacitive Technique

2013 ◽  
Vol 61 (2) ◽  
Author(s):  
Mohamad Faizal Abdullah ◽  
P. L. Leow ◽  
M. A. Abd Razak ◽  
F. K. Che Harun
Keyword(s):  
Low Cost ◽  
Microfluidic Channel ◽  
High Sensitivity ◽  
Microfluidic Devices ◽  
Capacitive Sensor ◽  
Sample Volume ◽  
Microfluidic System ◽  
Coplanar Electrodes ◽  
On Chip ◽  
Significant Attention

Significant attention has been given on the development of droplets–based microfluidic system because of its potential and apparent advantages. Beside the advantages of reducing the sample volume, it’s also offer less time consuming for the analysis. Optical and fluorescence among the famous method that was used in detection of droplets but they are normally bulky, expensive and not easily accessed. This paper proposed a simple, low cost and high sensitivity for droplets sensing in microfluidic devices by using capacitive sensor. Coplanar electrodes are used to form a capacitance through the microfluidic channel. The design of eight pair of electrodes was used to detect the presence of a droplet. Changes in capacitance due to the presence of a droplet in the sensing area is detected and used to trigger the microscope to capture the image of detected droplets in microchannel. The measurement of droplets detected and counting are displayed through a LABVIEW interface in the real time.

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