scholarly journals Droplet-based lab-on-chip platform integrated with laser ablated graphene heaters to synthesize gold nanoparticles for electrochemical sensing and fuel cell applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sangam Srikanth ◽  
Sohan Dudala ◽  
U. S. Jayapiriya ◽  
J. Murali Mohan ◽  
Sushil Raut ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Laser Power ◽  
Scanning Speed ◽  
Electrochemical Sensing ◽  
Biofuel Cell ◽  
Maximum Temperature ◽  
Lab On Chip ◽  
Wide Range ◽  
On Chip ◽  
Effective Use

AbstractControlled, stable and uniform temperature environment with quick response are crucial needs for many lab-on-chip (LOC) applications requiring thermal management. Laser Induced Graphene (LIG) heater is one such mechanism capable of maintaining a wide range of steady state temperature. LIG heaters are thin, flexible, and inexpensive and can be fabricated easily in different geometric configurations. In this perspective, herein, the electro-thermal performance of the LIG heater has been examined for different laser power values and scanning speeds. The experimented laser ablated patterns exhibited varying electrical conductivity corresponding to different combinations of power and speed of the laser. The conductivity of the pattern can be tailored by tuning the parameters which exhibit, a wide range of temperatures making them suitable for diverse lab-on-chip applications. A maximum temperature of 589 °C was observed for a combination of 15% laser power and 5.5% scanning speed. A LOC platform was realized by integrating the developed LIG heaters with a droplet-based microfluidic device. The performance of this LOC platform was analyzed for effective use of LIG heaters to synthesize Gold nanoparticles (GNP). Finally, the functionality of the synthesized GNPs was validated by utilizing them as catalyst in enzymatic glucose biofuel cell and in electrochemical applications.

scholarly journals Fabrication of Micro-channels using CO2 LASER Machining & Soft Lithography for Lab-on-Chip Applications

2021 ◽  
Author(s):  
Avinash K Parkhe ◽  
Amol Dhondiba Sul ◽  
Prathmesh Ramesh Kirgat ◽  
Atharv Santosh Joshi ◽  
Prakash Bhimrao Ghadage ◽  
...  
Keyword(s):  
Co2 Laser ◽  
Laser Power ◽  
Soft Lithography ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Laser Machining ◽  
Lab On Chip ◽  
Micro Channels ◽  
Acrylic Sheet ◽  
On Chip

Microchannels are one of the most significant parts for the Lab-on-Chip applications. The microchannels fabrication is a crucial task. The Soft Lithography is one of the most favored methods of microchannel fabrication. The use of CO2 LASER machining for microchannel fabrication using Acrylic sheet is studied in this paper. The experimentation is carried out to see the effect of LASER scanning speed and laser power on the depth of the microchannel mold. It has observed that the channel depth is increasing linearly with increasing LASER power and decreasing with increase in speed. The straight microchannel configuration with Y shaped inlet having circular & elliptical obstacles has been fabricated using CO2 laser machining on acrylic sheet. Also, the fabricated molds are used to prepare the further microchannel molds using the Soft Lithography technique and then the microchannels prepared from Soft Lithography are used as a mold for the lab-on-chip applications like check the mixing length & mixing phenomenon etc.

Elimination of Clogging in PMMA Microchannels Using Water Assisted CO2 Laser Micromachining

2015 ◽  
Vol 799-800 ◽  
pp. 407-412 ◽  
Author(s):  
Mohamed O. Helmy ◽  
Ahmed M. Fath El-Bab ◽  
Hassan El-Hofy
Keyword(s):  
Thin Layer ◽  
Heat Affected Zone ◽  
Scanning Speed ◽  
Fluid Mixing ◽  
Mixing Efficiency ◽  
Water Cooling ◽  
Quick Method ◽  
Lab On Chip ◽  
On Chip

The accuracy and clogging of microchannels are important for assessing the quality of lab on chip (L-O-C) devices. The clogging affects the fluid mixing efficiency and influences the bonding of substrate. In this paper, inexpensive and quick method for microchannel fabrication in polymethyl methacrylate (PMMA) while reducing the thermal damage is introduced. Accordingly, the substrate was covered with a thin layer of water during CO2laser ablation. The effect of water cooling on the clogging formation, heat affected zone and the microchannel geometry in terms of depth and width is investigated. Clogging formation mechanism in the intersection of Y-channel is studied to improve its quality for microfluidics applications. During the experimental work, the CO2laser power was varied from 2.4 to 6 W at scanning speed from 5 to 12.5 mm/s. The results showed that covering the PMMA substrate with a thin layer of water prevented clogging formation and reduced the heat affected zone.

scholarly journals Numerical Simulation of Moving Heat Flux during Selective Laser Melting of AlSi25 Alloy Powder

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 877
Author(s):  
Cong Ma ◽  
Xianshun Wei ◽  
Biao Yan ◽  
Pengfei Yan
Keyword(s):  
Numerical Simulation ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Molten Pool ◽  
Laser Power ◽  
Scanning Speed ◽  
Powder Layer ◽  
Maximum Temperature ◽  
Three Dimensional Model ◽  
Laser Melting

A single-layer three-dimensional model was created to simulate multi-channel scanning of AlSi25 powder in selective laser melting (SLM) by the finite element method. Thermal behaviors of laser power and scanning speed in the procedure of SLM AlSi25 powder were studied. With the increase of laser power, the maximum temperature, size and cooling rate of the molten pool increase, while the scanning speed decreases. For an expected SLM process, a perfect molten pool can be generated using process parameters of laser power of 180 W and a scanning speed of 200 mm/s. The pool is greater than the width of the scanning interval, the depth of the molten pool is close to scan powder layer thickness, the temperature of the molten pool is higher than the melting point temperature of the powder and the parameters of the width and depth are the highest. To confirm the accuracy of the simulation results of forecasting excellent process parameters, the SLM experiment of forming AlSi25 powder was carried out. The surface morphology of the printed sample is intact without holes and defects, and a satisfactory metallurgical bond between adjacent scanning channels and adjacent scanning layers was achieved. Therefore, the development of numerical simulation in this paper provides an effective method to obtain the best process parameters, which can be used as a choice to further improve SLM process parameters. In the future, metallographic technology can also be implemented to obtain the width-to-depth ratio of the SLM sample molten pool, enhancing the connection between experiment and theory.

scholarly journals Industry Partnership: Lab on Chip Chemical Sensor Technology for Ocean Observing

2021 ◽  
Vol 8 ◽  
Author(s):  
Matt Mowlem ◽  
Alexander Beaton ◽  
Robin Pascal ◽  
Allison Schaap ◽  
Socratis Loucaides ◽  
...  
Keyword(s):  
Chemical Sensor ◽  
Autonomous Underwater Vehicles ◽  
Product Line ◽  
The Arctic ◽  
Sensor Technology ◽  
Lab On Chip ◽  
Chip Technology ◽  
Wide Range ◽  
On Chip

We introduce for the first time a new product line able to make high accuracy measurements of a number of water chemistry parameters in situ: i.e., submerged in the environment including in the deep sea (to 6,000 m). This product is based on the developments of in situ lab on chip technology at the National Oceanography Centre (NOC), and the University of Southampton and is produced under license by Clearwater Sensors Ltd., a start-up and industrial partner in bringing this technology to global availability and further developing its potential. The technology has already been deployed by the NOC, and with their partners worldwide over 200 times including to depths of ∼4,800 m, in turbid estuaries and rivers, and for up to a year in seasonally ice-covered regions of the arctic. The technology is capable of making accurate determinations of chemical and biological parameters that require reagents and which produce an electrical, absorbance, fluorescence, or luminescence signal. As such it is suitable for a wide range of environmental measurements. Whilst further parameters are in development across this partnership, Nitrate, Nitrite, Phosphate, Silicate, Iron, and pH sensors are currently available commercially. Theses sensors use microfluidics and optics combined in an optofluidic chip with electromechanical valves and pumps mounted upon it to mix water samples with reagents and measure the optical response. An overview of the sensors and the underlying components and technologies is given together with examples of deployments and integrations with observing platforms such as gliders, autonomous underwater vehicles and moorings.

On Two Phase Flow Regimes in a Microscale Direct Methanol Fuel Cell

2008 ◽  
Author(s):  
Christian Weinmu¨ller ◽  
Nicole R. Bieri ◽  
Dimos Poulikakos
Keyword(s):  
Fuel Cell ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Research Attention ◽  
Lab On Chip ◽  
Research Activities ◽  
Wide Range ◽  
Direct Methanol ◽  
On Chip

The area of microfluidics has experienced a tremendous increase in research activities in recent years with a wide range of applications, such as micro heat exchangers and energy conversion devices, microreactors, lab-on-chip devices, micro total chemical analysis systems (μTAS) etc. The occurrence of two phase flow can lead to several mechanisms enhancing or extending the performance of single phase microfluidic devices [1]. On the other hand, in a micro fuel cell the second, non-immiscible phase is considered to hamper the performance of the fuel cell [2]. Regardless of its effect, two phase flows in microfluidics deserve special research attention.

scholarly journals Towards a Multifunctional Electrochemical Sensing and Niosome Generation Lab-on-Chip Platform Based on a Plug-and-Play Concept

Sensors ◽  
2016 ◽  
Vol 16 (6) ◽  
pp. 778 ◽  
Author(s):  
Adnane Kara ◽  
Camille Rouillard ◽  
Jessy Mathault ◽  
Martin Boisvert ◽  
Frédéric Tessier ◽  
...  
Keyword(s):  
Electrochemical Sensing ◽  
Plug And Play ◽  
Lab On Chip ◽  
On Chip

scholarly journals Polymer multilevel lab-on-chip systems for electrochemical sensing

2013 ◽  
Vol 31 (6) ◽  
pp. 06F904 ◽  
Author(s):  
Marco Matteucci ◽  
Simon Tylsgaard Larsen ◽  
Alessandro Garau ◽  
Simone Tanzi ◽  
Rafael Taboryski
Keyword(s):  
Electrochemical Sensing ◽  
Lab On Chip ◽  
On Chip

scholarly journals Printable graphene BioFETs for DNA quantification in Lab-on-PCB microsystems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sotirios Papamatthaiou ◽  
Pedro Estrela ◽  
Despina Moschou
Keyword(s):  
Printed Circuit Board ◽  
Point Of Care ◽  
Dna Amplification ◽  
Electrochemical Sensing ◽  
Circuit Board ◽  
Label Free ◽  
Transistor Channel ◽  
Lab On Chip ◽  
Passive Electrode ◽  
On Chip

AbstractLab-on-Chip is a technology that aims to transform the Point-of-Care (PoC) diagnostics field; nonetheless a commercial production compatible technology is yet to be established. Lab-on-Printed Circuit Board (Lab-on-PCB) is currently considered as a promising candidate technology for cost-aware but simultaneously high specification applications, requiring multi-component microsystem implementations, due to its inherent compatibility with electronics and the long-standing industrial manufacturing basis. In this work, we demonstrate the first electrolyte gated field-effect transistor (FET) DNA biosensor implemented on commercially fabricated PCB in a planar layout. Graphene ink was drop-casted to form the transistor channel and PNA probes were immobilized on the graphene channel, enabling label-free DNA detection. It is shown that the sensor can selectively detect the complementary DNA sequence, following a fully inkjet-printing compatible manufacturing process. The results demonstrate the potential for the effortless integration of FET sensors into Lab-on-PCB diagnostic platforms, paving the way for even higher sensitivity quantification than the current Lab-on-PCB state-of-the-art of passive electrode electrochemical sensing. The substitution of such biosensors with our presented FET structures, promises further reduction of the time-to-result in microsystems combining sequential DNA amplification and detection modules to few minutes, since much fewer amplification cycles are required even for low-abundance nucleic acid targets.

scholarly journals Biosensors in Health Care: The Milestones Achieved in Their Development towards Lab-on-Chip-Analysis

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Suprava Patel ◽  
Rachita Nanda ◽  
Sibasish Sahoo ◽  
Eli Mohapatra
Keyword(s):  
Point Of Care ◽  
Medical Diagnostics ◽  
Point Of Care Testing ◽  
Lab On Chip ◽  
Testing Facility ◽  
Wide Range ◽  
On Chip ◽  
Huge Challenge ◽  
Chip Analysis ◽  
Higher Sensitivity

Immense potentiality of biosensors in medical diagnostics has driven scientists in evolution of biosensor technologies and innovating newer tools in time. The cornerstone of the popularity of biosensors in sensing wide range of biomolecules in medical diagnostics is due to their simplicity in operation, higher sensitivity, ability to perform multiplex analysis, and capability to be integrated with different function by the same chip. There remains a huge challenge to meet the demands of performance and yield to its simplicity and affordability. Ultimate goal stands for providing point-of-care testing facility to the remote areas worldwide, particularly the developing countries. It entails continuous development in technology towards multiplexing ability, fabrication, and miniaturization of biosensor devices so that they can provide lab-on-chip-analysis systems to the community.

A Streaming Flow Based Lab-on-Chip Platform Technology

2008 ◽  
Author(s):  
Zongqin Zhang ◽  
Ahmed Fadl ◽  
Chang Liu ◽  
Donna Meyer
Keyword(s):  
First Generation ◽  
Cost Effective ◽  
Mean Velocity ◽  
Lab On Chip ◽  
Wide Range ◽  
Micro Array ◽  
Fluid Particles ◽  
Function Integration ◽  
On Chip ◽  
System Miniaturization

Numerous studies on microfluidics diagnostic devices have been published in the last decade. Although the first generation of Lab-on-chip (LOC) devices was functional in 1999, some of the promises of microfluidics (integration of all functions on a chip and the commercialization of truly handheld microfluidic instruments) have yet to be fulfilled. The major challenges of LOC technology include cost–effective pumping, function integration, multiple detection, and system miniaturization. In this paper, we propose a novel and simple streaming-based LOC technology that may have potential to directly address these challenges. The phenomenon of the flow streaming is found in zero-mean velocity oscillating flows in a wide range of channel geometries. Although there is no net flow (zero-mean velocity) across the channel, a discrepancy in velocity profiles between the forward flow and backward flow causes fluid particles near the walls to drift toward one end, while fluid particles near the centerline drift to the other end. We hypothesize that the unique characteristics of flow streaming could be used: 1) to transport, mix and separate particles/molecules/bacterium/cells entrained in flows; 2) to perform multi-channel/generation micro-array sample distributions; and 3) to achieve function integrations and biomarker detections. Mechanisms of using flow streaming to achieve the various LOC functions are described. Preliminary results are presented to demonstrate the potential of this technology for LOC applications.

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