Photopatterning of hydrogel microarryas in closed microchips

Research output: Contribution to journalArticleAcademicpeer-review

11 Citations (Scopus)

Abstract

To date, optical lithography has been extensively used for in situ patterning of hydrogel structures in a scale range from hundreds of microns to a few millimeters. The two main limitations which prevent smaller feature sizes of hydrogel structures are (1) the upper glass layer of a microchip maintains a large spacing (typically 525 mu m) between the photomask and hydrogel precursor, leading to diffraction of UV light at the edges of mask patterns, (2) diffusion of free radicals and monomers results in irregular polymerization near the illumination interface. In this work, we present a simple approach to enable the use of optical lithography to fabricate hydrogel arrays with a minimum feature size of 4 mu m inside closed microchips. To achieve this, we combined two different techniques. First, the upper glass layer of the microchip was thinned by mechanical polishing to reduce the spacing between the photomask and hydrogel precursor, and thereby the diffraction of UV light at the edges of mask patterns. The polishing process reduces the upper layer thickness from similar to 525 to similar to 100 mu m, and the mean surface roughness from 20 to 3 nm. Second, we developed an intermittent illumination technique consisting of short illumination periods followed by relatively longer dark periods, which decrease the diffusion of monomers. Combination of these two methods allows for fabrication of 0.4 x 10(6) sub-10 mu m sized hydrogel patterns over large areas (cm(2)) with high reproducibility (similar to 98.5% patterning success). The patterning method is tested with two different types of photopolymerizing hydrogels: polyacrylamide and polyethylene glycol diacrylate. This method enables in situ fabrication of well-defined hydrogel patterns and presents a simple approach to fabricate 3-D hydrogel matrices for biomolecule separation, biosensing, tissue engineering, and immobilized protein microarray applications
Original languageUndefined
Pages (from-to)3802-3810
Number of pages9
JournalBiomacromolecules
Volume16
Issue number12
DOIs
Publication statusPublished - Dec 2015

Keywords

  • EWI-27094
  • METIS-318467
  • IR-101015
  • 10.1021/acs.biomac.5b01104

Cite this

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title = "Photopatterning of hydrogel microarryas in closed microchips",
abstract = "To date, optical lithography has been extensively used for in situ patterning of hydrogel structures in a scale range from hundreds of microns to a few millimeters. The two main limitations which prevent smaller feature sizes of hydrogel structures are (1) the upper glass layer of a microchip maintains a large spacing (typically 525 mu m) between the photomask and hydrogel precursor, leading to diffraction of UV light at the edges of mask patterns, (2) diffusion of free radicals and monomers results in irregular polymerization near the illumination interface. In this work, we present a simple approach to enable the use of optical lithography to fabricate hydrogel arrays with a minimum feature size of 4 mu m inside closed microchips. To achieve this, we combined two different techniques. First, the upper glass layer of the microchip was thinned by mechanical polishing to reduce the spacing between the photomask and hydrogel precursor, and thereby the diffraction of UV light at the edges of mask patterns. The polishing process reduces the upper layer thickness from similar to 525 to similar to 100 mu m, and the mean surface roughness from 20 to 3 nm. Second, we developed an intermittent illumination technique consisting of short illumination periods followed by relatively longer dark periods, which decrease the diffusion of monomers. Combination of these two methods allows for fabrication of 0.4 x 10(6) sub-10 mu m sized hydrogel patterns over large areas (cm(2)) with high reproducibility (similar to 98.5{\%} patterning success). The patterning method is tested with two different types of photopolymerizing hydrogels: polyacrylamide and polyethylene glycol diacrylate. This method enables in situ fabrication of well-defined hydrogel patterns and presents a simple approach to fabricate 3-D hydrogel matrices for biomolecule separation, biosensing, tissue engineering, and immobilized protein microarray applications",
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author = "B. G{\"u}m{\"u}sc{\"u} and Bomer, {Johan G.} and {van den Berg}, Albert and Eijkel, {Jan C.T.}",
note = "10.1021/acs.biomac.5b01104",
year = "2015",
month = "12",
doi = "10.1021/acs.biomac.5b01104",
language = "Undefined",
volume = "16",
pages = "3802--3810",
journal = "Biomacromolecules",
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Photopatterning of hydrogel microarryas in closed microchips. / Gümüscü, B.; Bomer, Johan G.; van den Berg, Albert; Eijkel, Jan C.T.

In: Biomacromolecules, Vol. 16, No. 12, 12.2015, p. 3802-3810.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Photopatterning of hydrogel microarryas in closed microchips

AU - Gümüscü, B.

AU - Bomer, Johan G.

AU - van den Berg, Albert

AU - Eijkel, Jan C.T.

N1 - 10.1021/acs.biomac.5b01104

PY - 2015/12

Y1 - 2015/12

N2 - To date, optical lithography has been extensively used for in situ patterning of hydrogel structures in a scale range from hundreds of microns to a few millimeters. The two main limitations which prevent smaller feature sizes of hydrogel structures are (1) the upper glass layer of a microchip maintains a large spacing (typically 525 mu m) between the photomask and hydrogel precursor, leading to diffraction of UV light at the edges of mask patterns, (2) diffusion of free radicals and monomers results in irregular polymerization near the illumination interface. In this work, we present a simple approach to enable the use of optical lithography to fabricate hydrogel arrays with a minimum feature size of 4 mu m inside closed microchips. To achieve this, we combined two different techniques. First, the upper glass layer of the microchip was thinned by mechanical polishing to reduce the spacing between the photomask and hydrogel precursor, and thereby the diffraction of UV light at the edges of mask patterns. The polishing process reduces the upper layer thickness from similar to 525 to similar to 100 mu m, and the mean surface roughness from 20 to 3 nm. Second, we developed an intermittent illumination technique consisting of short illumination periods followed by relatively longer dark periods, which decrease the diffusion of monomers. Combination of these two methods allows for fabrication of 0.4 x 10(6) sub-10 mu m sized hydrogel patterns over large areas (cm(2)) with high reproducibility (similar to 98.5% patterning success). The patterning method is tested with two different types of photopolymerizing hydrogels: polyacrylamide and polyethylene glycol diacrylate. This method enables in situ fabrication of well-defined hydrogel patterns and presents a simple approach to fabricate 3-D hydrogel matrices for biomolecule separation, biosensing, tissue engineering, and immobilized protein microarray applications

AB - To date, optical lithography has been extensively used for in situ patterning of hydrogel structures in a scale range from hundreds of microns to a few millimeters. The two main limitations which prevent smaller feature sizes of hydrogel structures are (1) the upper glass layer of a microchip maintains a large spacing (typically 525 mu m) between the photomask and hydrogel precursor, leading to diffraction of UV light at the edges of mask patterns, (2) diffusion of free radicals and monomers results in irregular polymerization near the illumination interface. In this work, we present a simple approach to enable the use of optical lithography to fabricate hydrogel arrays with a minimum feature size of 4 mu m inside closed microchips. To achieve this, we combined two different techniques. First, the upper glass layer of the microchip was thinned by mechanical polishing to reduce the spacing between the photomask and hydrogel precursor, and thereby the diffraction of UV light at the edges of mask patterns. The polishing process reduces the upper layer thickness from similar to 525 to similar to 100 mu m, and the mean surface roughness from 20 to 3 nm. Second, we developed an intermittent illumination technique consisting of short illumination periods followed by relatively longer dark periods, which decrease the diffusion of monomers. Combination of these two methods allows for fabrication of 0.4 x 10(6) sub-10 mu m sized hydrogel patterns over large areas (cm(2)) with high reproducibility (similar to 98.5% patterning success). The patterning method is tested with two different types of photopolymerizing hydrogels: polyacrylamide and polyethylene glycol diacrylate. This method enables in situ fabrication of well-defined hydrogel patterns and presents a simple approach to fabricate 3-D hydrogel matrices for biomolecule separation, biosensing, tissue engineering, and immobilized protein microarray applications

KW - EWI-27094

KW - METIS-318467

KW - IR-101015

KW - 10.1021/acs.biomac.5b01104

U2 - 10.1021/acs.biomac.5b01104

DO - 10.1021/acs.biomac.5b01104

M3 - Article

VL - 16

SP - 3802

EP - 3810

JO - Biomacromolecules

JF - Biomacromolecules

SN - 1525-7797

IS - 12

ER -