Single step sequential polydimethylsiloxane wet etching to fabricate a microfluidic channel with various cross-sectional geometries

Wang, Chien-Kai; Liao, Wei-Hao; Wu, Hsiao-Mei; Lo, Yu‐Hwa; Lin, Ting-Ru; Tung, Yi-Chung

doi:10.1088/1361-6439/aa874d

Cited by 3 publications

(6 citation statements)

References 29 publications

(30 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The proof-of-concept chip design used to demonstrate the mold fabrication technique is based on the 3D flow focusing design of Chiu et al [114]. There are advantages that this mold fabrication technique provides over other methods [145,146], but the sealing step is an extra step not present in most fabrication techniques. However, the sealing step does not hamper the utilization of the device.…”

Section: Fabrication Of Mold For 3d Flow Focusing Devicementioning

confidence: 99%

“…As explained in Section 4.1, fabrication of PDMS devices for 3D flow focusing applications relying on conventional techniques such as multilayer soft lithography [164] or photolithography [145,146], is difficult since different channel heights are required. While 2D flow focusing is quite ubiquitous in microfluidics [165,166], 3D flow focusing applications often require sophisticated manufacturing procedures.…”

Section: Flow Focusing Device Testmentioning

confidence: 99%

“…This 3D microfluidic geometry is difficult to fabricate using conventional planar mold manufacturing techniques [143,144]. It is also time-consuming to make such molds using soft lithography and two-step molding [145,146], and newer methods such as electroplating nickel molds [47]. Therefore, fabrication of 3D flow focusing geometries can be made much simpler by avoiding strategies that rely on layer-by-layer photolithography [147].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Fabrication of Free-Standing Structures Using Abrasive/Slurry Jet Micro-Machining

Azarsa¹

2023

Preprint

View full text Add to dashboard Cite

Many advanced engineering materials are machined using abrasive water jets, a non-traditional machining method that has certain advantages compared to other approaches. This dissertation aims at developing methodologies to use abrasive water and slurry jets to micro-machine free-standing structures for heat sink and microfluidics applications. The first aim was to fabricate high aspect ratio free-standing structures with a minimum distance between each other that would lead to maximum heat transfer performance in heat sinks. The effect of machining process parameters on the quality of the resulting free-standing structures was studied. It was demonstrated that high-quality free-standing structures with aspect ratios of more than 40 to be used as fins in heat sinks could be fabricated. There is an increasing demand for metallic micro-molds that can be used for inexpensive mass production of polymeric microfluidic chips. Therefore, the feasibility of using abrasive water jet micro-machining (AWJM) and abrasive slurry jet micro-machining (ASJM) to fabricate such micro-molds was studied. Jet raster scans under various combinations of process parameters were used in order to machine micro-pockets containing free-standing structures, representing molds for casting microfluidic chips with channel networks. The optimum process parameters and material were determined in order to fabricate the molds with the best possible surface finish. Because unmasked machining could not be used to fabricate molds with sharp-edged intersecting features, a hybrid AWJM/ASJM masked machining technique was introduced. By careful selection of the process parameters, high quality molds with both single and intersecting free-standing structures at multiple heights could be fabricated, thus making three-dimensional microfluidic chip mold fabrication feasible. Finally, a new method of mold fabrication that utilized water jet cutting technology to cut free-standing structures out of mild steel sheets, to be used as a mold for PDMS casting, was developed. This enabled 3D features having very abrupt changes in depth with almost 90o angles for use in microfluidic devices. As a proof-of-concept, a polydimethylsiloxane (PDMS) chip was made and tested. It was shown that this alternative approach to create microfluidic molds is versatile and may find utility in reducing the cost and complexity involved in fabricating 3D features in microfluidic devices.

show abstract

Section: Fabrication Of Mold For 3d Flow Focusing Devicementioning

confidence: 99%

Section: Flow Focusing Device Testmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fabrication of Free-Standing Structures Using Abrasive/Slurry Jet Micro-Machining

Azarsa¹

2023

Preprint

View full text Add to dashboard Cite

show abstract

“…There are advantages that this mold fabrication technique provides over other methods, 40,41 but the sealing step is an extra step not present in most fabrication techniques. However, the sealing step does not hamper the utilization of the device.…”

Section: (H)mentioning

confidence: 99%

“…37 This 3D microfluidic geometry is difficult to fabricate using conventional planar mold manufacturing techniques. 38,39 It is also time-consuming to make such molds using soft lithography and two-step molding, 40,41 and newer methods such as electroplating nickel molds. 42 Therefore, the fabrication of 3D flow focusing geometries can be made much simpler by avoiding strategies that rely on layer-by-layer photolithography.…”

Section: Introductionmentioning

confidence: 99%

A novel abrasive water jet machining technique for rapid fabrication of three-dimensional microfluidic components

et al. 2020

View full text Add to dashboard Cite

Microfluidic lab-on-a-chip devices are usually fabricated using replica molding, with poly(dimethylsiloxane) (PDMS) casting on a mold. Most common techniques used to fabricate microfluidic molds, such as photolithography and soft lithography, require costly facilities such as a cleanroom, and complicated steps, especially for the fabrication of three-dimensional (3D) features. For example, an often-desired 3D microchannel feature consists of intersecting channels with depth variations. This type of 3D flow focusing geometry has applications in flow cytometry and droplet generation. Various manufacturing techniques have recently been developed for the rapid fabrication of such 3D microfluidic features. In this paper, we describe a new method of mold fabrication that utilizes water jet cutting technology to fabricate free-standing structures on mild steel sheets to make a mold for PDMS casting. As a proof-of-concept, we use this fabrication technique to make a PDMS chip that has a 3D flow focusing junction, an inlet for the sample fluid, two inlets for the sheath fluid, and an outlet. The flow focusing junction is patterned into the PDMS slab with an abrupt, nearly stepwise change to the depth of the microchannel junction. We use confocal microscopy to visualize the 3D flow focusing of a sample flow using this geometry, and we also use the same geometry to generate water-in-oil droplets. This alternative approach to create microfluidic molds is versatile and may find utility in reducing the cost and complexity involved in fabricating 3D features in microfluidic devices.

show abstract

A novel abrasive water jet machining technique for rapid fabrication of three-dimensional microfluidic components

Azarsa,

Jeyhani,

Ibrahim

et al. 2024

Preprint

View full text Add to dashboard Cite

Microfluidic lab-on-a-chip devices are usually fabricated using replica molding, with poly(dimethylsiloxane) (PDMS) casting on a mold. Most common techniques used to fabricate microfluidic molds, such as photolithography and soft lithography, require costly facilities such as a cleanroom, and complicated steps, especially for the fabrication of three-dimensional (3D) features. For example, an often-desired 3D microchannel feature consists of intersecting channels with depth variations. This type of 3D flow focusing geometry has applications in flow cytometry and droplet generation. Various manufacturing techniques have recently been developed for the rapid fabrication of such 3D microfluidic features. In this paper, we describe a new method of mold fabrication that utilizes water jet cutting technology to fabricate free-standing structures on mild steel sheets to make a mold for PDMS casting. As a proof-of-concept, we use this fabrication technique to make a PDMS chip that has a 3D flow focusing junction, an inlet for the sample fluid, two inlets for the sheath fluid, and an outlet. The flow focusing junction is patterned into the PDMS slab with an abrupt, nearly stepwise change to the depth of the microchannel junction. We use confocal microscopy to visualize the 3D flow focusing of a sample flow using this geometry, and we also use the same geometry to generate water-in-oil droplets. This alternative approach to create microfluidic molds is versatile and may find utility in reducing the cost and complexity involved in fabricating 3D features in microfluidic devices.

show abstract

Single step sequential polydimethylsiloxane wet etching to fabricate a microfluidic channel with various cross-sectional geometries

Cited by 3 publications

References 29 publications

Fabrication of Free-Standing Structures Using Abrasive/Slurry Jet Micro-Machining

Fabrication of Free-Standing Structures Using Abrasive/Slurry Jet Micro-Machining

A novel abrasive water jet machining technique for rapid fabrication of three-dimensional microfluidic components

A novel abrasive water jet machining technique for rapid fabrication of three-dimensional microfluidic components

Contact Info

Product

Resources

About