Abstract
A microfluidic probe (MFP) does not require physical walls for flow channels, enabling application of a chemical solution in an open space by injecting and aspirating the solution. However, in conventional MFP fabrication methods, the use of a 2D aperture array at narrow intervals to enhance the function of treatment remains limited. In this study, we developed a stainless MFP (stMFP) to produce a 2D aperture array at narrow intervals. The stMFP was developed using a stacking technique in which stainless steel substrates fabricated by photolithography and a wet etching process were stacked and bonded through thermal diffusion. This process resulted in a 6-row and 8-column aperture array with an aperture size of 100 × 150 µm and a narrow interval of 50 µm. The surface treatment area was evaluated by biopatterning of a fluorescent antibody. The results showed that the stMFP biopatterned a minimum treatment area of 3.3 × 103 µm2, which could be controlled between 5.1 × 104 µm2 and 3.0 × 105 µm2 by changing the aperture arrangement. In addition, when two types of fluorescent antibodies were alternately injected in the row direction, six independent treatment areas of 6.1 × 104 µm2 were formed over a wide area of 3.8 × 105 µm2. Furthermore, biopatterning using a 4 × 4 aperture array showed that a 2D treatment area with 4-rows and 2-columns can be produced with an area of 4.5 × 105 µm2. A single stMFP can form various 2D treatment patterns, which is expected to realize high-performance bioprocessing in the field of biology.
Highlights
Microfluidic probes (MFPs) have attracted attention as devices that enable local chemical treatment in a solution without introducing samples into channels constructed with physical walls
We propose a fabrication scheme based on the stacking and bonding of microfabricated stainless steel substrates to generate a 2D aperture array and developed a stainless MFP with a 6-row and 8-column aperture array with an aperture size of 100 × 150 μm at narrow intervals of 50 μm
We developed an stainless MFP (stMFP) with 48 apertures in a 6-row and 8-column aperture array by stacking seven partition layers and six microchannel layers for multifunctional and simultaneous 2D flow patterning
Summary
Scitation.org/journal/adv limited to two rows, and no MFP with three or more rows to form 2D aperture arrays with narrow spacing has been reported, as far as we have investigated. In conventional methods for fabricating an MFP, polydimethylsiloxane, glass, and silicon substrates have been employed, this method makes it difficult to form multilayer stacks of thin layers because of their physical properties and limitations in the fabrication process To overcome these limitations, we used stainless steel substrates with high rigidity and chemical resistance to allow for facile bonding operations for thin substrates.. Stainless steel has high chemical resistance, enabling the removal of organic stain from the device with an organic solvent and strong alkaline solution, as well as reusing the stMFP after experiments involving biosamples In this fabrication scheme, increasing the number of stacking layers and microchannels in a single. By observing the fluorescence of the antibody attached to the glass substrate under an optical microscope, the treatment area can be estimated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
