scholarly journals Micro–Macro: Selective Integration of Microfeatures Inside Low-Cost Macromolds for PDMS Microfluidics Fabrication

Micromachines ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 576 ◽  
Author(s):  
Edgar Jiménez-Díaz ◽  
Mariel Cano-Jorge ◽  
Diego Zamarrón-Hernández ◽  
Lucia Cabriales ◽  
Francisco Páez-Larios ◽  
...  
Keyword(s):  
Soft Lithography ◽  
Low Cost ◽  
Cost Effective ◽  
Microfluidic Chips ◽  
Single Chip ◽  
Lab On Chip ◽  
Molding Method ◽  
On Chip ◽  
Selective Integration ◽  
Important Progress

Microfluidics has become a very promising technology in recent years, due to its great potential to revolutionize life-science solutions. Generic microfabrication processes have been progressively made available to academic laboratories thanks to cost-effective soft-lithography techniques and enabled important progress in applications like lab-on-chip platforms using rapid- prototyping. However, micron-sized features are required in most designs, especially in biomimetic cell culture platforms, imposing elevated costs of production associated with lithography and limiting the use of such devices. In most cases, however, only a small portion of the structures require high-resolution and cost may be decreased. In this work, we present a replica-molding method separating the fabrication steps of low (macro) and high (micro) resolutions and then merging the two scales in a single chip. The method consists of fabricating the largest possible area in inexpensive macromolds using simple techniques such as plastics micromilling, laser microfabrication, or even by shrinking printed polystyrene sheets. The microfeatures were made on a separated mold or onto existing macromolds using photolithography or 2-photon lithography. By limiting the expensive area to the essential, the time and cost of fabrication can be reduced. Polydimethylsiloxane (PDMS) microfluidic chips were successfully fabricated from the constructed molds and tested to validate our micro–macro method.

On-Site Monitoring of Steroid Hormones in Environmental Waters with a Low-Cost, Integrated Polymer Lab-on-Chip Device

2013 ◽  
Vol 448-453 ◽  
pp. 396-401
Author(s):  
Nuno Miguel Matos Pires ◽  
Tao Dong
Keyword(s):  
Steroid Hormones ◽  
Optical Sensors ◽  
Water Samples ◽  
Low Cost ◽  
Cost Effective ◽  
Environmental Water ◽  
Lab On Chip ◽  
Gold Thin Film ◽  
Site Monitoring ◽  
On Chip

Routine analysis of steroid hormones in environmental water samples demands for cost-effective tools that can detect multiple targets simultaneously. This study reports a high-throughput polymer platform integrated to polymer optical sensors for on-site monitoring of hormones in water. This opto-microfluidic device concept is fully compatible to low-cost fabrication methods. A competitive chemiluminescence immunoassay was performed onto gold thin film coated chambers, and a detection resolution of roughly 0.2 ng/mL was obtained using 17β-estradiol as the model target. Furthermore, the integrated polymer platform showed good recovery for the estradiol target when spiked in surface water samples.

scholarly journals Increased Flexibility in Lab-on-Chip Design with a Polymer Patchwork Approach

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1678 ◽  
Author(s):  
Denise Pezzuoli ◽  
Elena Angeli ◽  
Diego Repetto ◽  
Patrizia Guida ◽  
Giuseppe Firpo ◽  
...  
Keyword(s):  
Soft Lithography ◽  
Low Cost ◽  
Chip Design ◽  
Lab On Chip ◽  
Force Microscopy ◽  
Roof Collapse ◽  
Flexible Devices ◽  
Atomic Force ◽  
On Chip ◽  
Critical Regions

Nanofluidic structures are often the key element of many lab-on-chips for biomedical and environmental applications. The demand for these devices to be able to perform increasingly complex tasks triggers a request for increasing the performance of the fabrication methods. Soft lithography and poly(dimethylsiloxane) (PDMS) have since long been the basic ingredients for producing low-cost, biocompatible and flexible devices, replicating nanostructured masters. However, when the desired functionalities require the fabrication of shallow channels, the “roof collapse” phenomenon, that can occur when sealing the replica, can impair the device functionalities. In this study, we demonstrate that a “focused drop-casting” of h-PDMS (hard PDMS) on nanostructured regions, provides the necessary stiffness to avoid roof collapse, without increasing the probability of deep cracks formation, a drawback that shows up in the peel-off step, when h-PDMS is used all over the device area. With this new approach, we efficiently fabricate working devices with reproducible sub-100 nm structures. We verify the absence of roof collapse and deep cracks by optical microscopy and, in order to assess the advantages that are introduced by the proposed technique, the acquired images are compared with those of cracked devices, whose top layer, of h-PDMS, and with those of collapsed devices, made of standard PDMS. The geometry of the critical regions is studied by atomic force microscopy of their resin casts. The electrical resistance of the nanochannels is measured and shown to be compatible with the estimates that can be obtained from the geometry. The simplicity of the method and its reliability make it suitable for increasing the fabrication yield and reducing the costs of nanofluidic polymeric lab-on-chips.

scholarly journals The Rise of the OM-LoC: Opto-Microfluidic Enabled Lab-on-Chip

Micromachines ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1467
Author(s):  
Harry Dawson ◽  
Jinane Elias ◽  
Pascal Etienne ◽  
Sylvie Calas-Etienne
Keyword(s):  
Low Cost ◽  
Optical Components ◽  
New Era ◽  
Lab On Chip ◽  
Highly Sensitive ◽  
Multiple Challenges ◽  
On Chip ◽  
Optical Circuits ◽  
Made In

The integration of optical circuits with microfluidic lab-on-chip (LoC) devices has resulted in a new era of potential in terms of both sample manipulation and detection at the micro-scale. On-chip optical components increase both control and analytical capabilities while reducing reliance on expensive laboratory photonic equipment that has limited microfluidic development. Notably, in-situ LoC devices for bio-chemical applications such as diagnostics and environmental monitoring could provide great value as low-cost, portable and highly sensitive systems. Multiple challenges remain however due to the complexity involved with combining photonics with micro-fabricated systems. Here, we aim to highlight the progress that optical on-chip systems have made in recent years regarding the main LoC applications: (1) sample manipulation and (2) detection. At the same time, we aim to address the constraints that limit industrial scaling of this technology. Through evaluating various fabrication methods, material choices and novel approaches of optic and fluidic integration, we aim to illustrate how optic-enabled LoC approaches are providing new possibilities for both sample analysis and manipulation.

Low cost optical particle detection for lab on chip systems based on DVD technology

2007 ◽  
Author(s):  
Andrew L. Clow ◽  
Rainer Künnemeyer ◽  
Paul Gaynor ◽  
John C. Sharpe
Keyword(s):  
Low Cost ◽  
Particle Detection ◽  
Lab On Chip ◽  
On Chip

Point-of-Care Systems for Rapid DNA Quantification in Oncology

2008 ◽  
Vol 94 (2) ◽  
pp. 216-225 ◽  
Author(s):  
Marco Bianchessi ◽  
Sarah Burgarella ◽  
Marco Cereda
Keyword(s):  
Point Of Care ◽  
Low Cost ◽  
Semiconductor Industry ◽  
Point Of Care Testing ◽  
Lab On Chip ◽  
Diagnostic Assays ◽  
Care Systems ◽  
Point Of Care Systems ◽  
The Common ◽  
On Chip

The development of new powerful applications and the improvement in fabrication techniques are promising an explosive growth in lab-on-chip use in the upcoming future. As the demand reaches significant levels, the semiconductor industry may enter in the field, bringing its capability to produce complex devices in large volumes, high quality and low cost. The lab-on-chip concept, when applied to medicine, leads to the point-of-care concept, where simple, compact and cheap instruments allow diagnostic assays to be performed quickly by untrained personnel directly at the patient's side. In this paper, some practical and economical considerations are made to support the advantages of point-of-care testing. A series of promising technologies developed by STMicroelectronics on lab-on-chips is also presented, mature enough to enter in the common medical practice. The possible use of these techniques for cancer research, diagnosis and treatment are illustrated together with the benefits offered by their implementation in point-of-care testing.

A low-cost, label-free DNA detection method in lab-on-chip format based on electrohydrodynamic instabilities, with application to long-range PCR

Lab on a Chip ◽  
2012 ◽  
Vol 12 (22) ◽  
pp. 4738 ◽  
Author(s):  
Mohamed Lemine Youba Diakité ◽  
Jerôme Champ ◽  
Stephanie Descroix ◽  
Laurent Malaquin ◽  
François Amblard ◽  
...  
Keyword(s):  
Long Range ◽  
Detection Method ◽  
Dna Detection ◽  
Low Cost ◽  
Label Free ◽  
Lab On Chip ◽  
Free Dna ◽  
Chip Format ◽  
Long Range Pcr ◽  
On Chip

scholarly journals An Intelligent Low-Power Low-Cost Mobile Lab-On-Chip Yeast Cell Culture Platform

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 70733-70745
Author(s):  
Yumin Liao ◽  
Ningmei Yu ◽  
Dian Tian ◽  
Chen Wang ◽  
Shuaijun Li ◽  
...  
Keyword(s):  
Cell Culture ◽  
Low Power ◽  
Yeast Cell ◽  
Low Cost ◽  
Lab On Chip ◽  
On Chip

Active High-Throughput Micromixer Using Injected Magnetic Mixture Underneath Microfluidic Channel

2020 ◽  
Author(s):  
Athira N. Surendran ◽  
Ran Zhou
Keyword(s):  
Soft Lithography ◽  
Permanent Magnets ◽  
Low Cost ◽  
Microfluidic Channel ◽  
Microfluidic Chips ◽  
Small Channel ◽  
Parametric Studies ◽  
Micro Level ◽  
Planar Location ◽  
Sample Dilution

Abstract Microfluidics has a lot of applications in fields ranging from pharmaceutical to energy, and one of the major applications is micromixers. A challenge faced by most micromixers is the difficulty in mixing within micro-size fluidic channels because of the domination of laminar flow in a small channel. Hence, magnetic field generated by permanent magnets and electromagnets have been widely used to mix ferrofluids with other sample fluids on a micro level. However, permanent magnets are bulky, and electromagnets produce harmful heat to biological samples; both properties are detrimental to a microfluidic chip’s performance. Taking these into consideration, this study proposes rapid mixing of ferrofluid using a two-layer microfluidic device with microfabricated magnet. Two microfluidic chips that consist of microchannels and micromagnets respectively are fabricated using a simple and low-cost soft lithography method. The custom-designed microscale magnet consists of an array of stripes and is bonded below the plane of the microchannel. The combination of the planar location and angle of the array of magnets allow the migration of ferrofluids, hence mixing it with buffer flow. Parametric studies are performed to ensure comprehensive understanding, including the angle of micro-scale magnets with respect to the fluidic channels, total flow rate and density of the array of magnets. The result from this study can be applied in chemical synthesis and pre-processing, sample dilution, or inducing reactions between samples and reagent.

Microfluidic Control Using Vapor Based Valves

2007 ◽  
Author(s):  
Wei Xu ◽  
Hong Xue ◽  
Mark Bachman ◽  
G. P. Li
Keyword(s):  
Temperature Gradient ◽  
Low Cost ◽  
Constant Flow ◽  
Lab On Chip ◽  
Air Pocket ◽  
Valve Function ◽  
Air Valve ◽  
On Chip ◽  
Silicon Based ◽  
At Will

Microflow valving and regulating are two important functions for microfluidic systems for applications such as Lab-on-Chip. Although silicon based counterparts have been studied extensively, few good technologies exist for polymer based microvalves and regulators. In this paper, we present designs and methods for microvalve and microflow regulators that are readily integrated into polymer microfluidic devices. The technologies utilize “air-pocket” structures built into the sidewalls of the microchannels. When liquid is filled in such a channel, air is trapped in “air pocket” structures due to the hydrophobicity of the polymer. By creating a small thermal gradient between the fluid in the channel and the air in the pockets, one can controllably evaporate fluid into the air pocket where it condenses. This displaces air out of the pocket into the flow channel, increasing the resistance to flow. The air valve retreats to its original pocket when the temperature gradient is removed, thus allowing one to increase or decrease fluid flow at will. If the temperature gradient is maintained long enough, the air will completely block the channel, forming an irreversible valving of the flow. Therefore, the same device can be used as either a valve or flow-regulating device. Microfluidic prototypes were built and tested using this technology. The results show successful constant flow delivery as well as valve function. This novel vapor based microflow valve and regulator has advantages of low cost, simple design, and both ease of fabrication and integration.

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