Fabrication and bonding of thiol-ene-based microfluidic devices: Technical Note

Tiina M Sikanen, Josiane P. Lafleur, Maria-Elisa Moilanen, Guisheng Zhuang, Thomas Glasdam Jensen, Jörg Peter Kutter

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    In this work, the bonding strength of microchips fabricated by thiol-ene free-radical polymerization was characterized in detail by varying the monomeric thiol/allyl composition from the stoichiometric ratio (1:1) up to 100% excess of thiol (2:1) or allyl (1:2) functional groups. Four different thiol-ene to thiol-ene bonding combinations were tested by bonding: (i) two stoichiometric layers, (ii) two layers bearing complementary excess of thiols and allyls, (iii) two layers both bearing excess of thiols, or (iv) two layers both bearing excess of allyls. The results showed that the stiffness of the cross-linked polymer plays the most crucial role regarding the bonding strength. The most rigid polymer layers were obtained by using the stoichiometric composition or an excess of allyls, and thus, the bonding combinations (i) and (iv) withstood the highest pressures (up to the cut-off value of 6 bar). On the other hand, excess of thiol monomers yielded more elastic polymer layers and thus decreased the pressure tolerance for bonding combinations (ii) and (iii). By using monomers with more thiol groups (e.g. tetrathiol versus trithiol), a higher cross-linking ratio, and thus, greater stiffness was obtained. Surface characterization by infrared spectroscopy confirmed that the changes in the monomeric thiol/allyl composition were also reflected in the surface chemistry. The flexibility of being able to bond different types of thiol-enes together allows for tuning of the surface chemistry to yield the desired properties for each application. Here, a capillary electrophoresis separation is performed to demonstrate the attractive properties of stoichiometric thiol-ene microchips.
    Original languageEnglish
    JournalJournal of Micromechanics and Microengineering
    Volume23
    Issue number3
    Number of pages7
    ISSN0960-1317
    DOIs
    Publication statusPublished - 2013

    Cite this

    Sikanen, Tiina M ; Lafleur, Josiane P. ; Moilanen, Maria-Elisa ; Zhuang, Guisheng ; Jensen, Thomas Glasdam ; Kutter, Jörg Peter. / Fabrication and bonding of thiol-ene-based microfluidic devices : Technical Note. In: Journal of Micromechanics and Microengineering. 2013 ; Vol. 23, No. 3.
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    title = "Fabrication and bonding of thiol-ene-based microfluidic devices: Technical Note",
    abstract = "In this work, the bonding strength of microchips fabricated by thiol-ene free-radical polymerization was characterized in detail by varying the monomeric thiol/allyl composition from the stoichiometric ratio (1:1) up to 100{\%} excess of thiol (2:1) or allyl (1:2) functional groups. Four different thiol-ene to thiol-ene bonding combinations were tested by bonding: (i) two stoichiometric layers, (ii) two layers bearing complementary excess of thiols and allyls, (iii) two layers both bearing excess of thiols, or (iv) two layers both bearing excess of allyls. The results showed that the stiffness of the cross-linked polymer plays the most crucial role regarding the bonding strength. The most rigid polymer layers were obtained by using the stoichiometric composition or an excess of allyls, and thus, the bonding combinations (i) and (iv) withstood the highest pressures (up to the cut-off value of 6 bar). On the other hand, excess of thiol monomers yielded more elastic polymer layers and thus decreased the pressure tolerance for bonding combinations (ii) and (iii). By using monomers with more thiol groups (e.g. tetrathiol versus trithiol), a higher cross-linking ratio, and thus, greater stiffness was obtained. Surface characterization by infrared spectroscopy confirmed that the changes in the monomeric thiol/allyl composition were also reflected in the surface chemistry. The flexibility of being able to bond different types of thiol-enes together allows for tuning of the surface chemistry to yield the desired properties for each application. Here, a capillary electrophoresis separation is performed to demonstrate the attractive properties of stoichiometric thiol-ene microchips.",
    author = "Sikanen, {Tiina M} and Lafleur, {Josiane P.} and Maria-Elisa Moilanen and Guisheng Zhuang and Jensen, {Thomas Glasdam} and Kutter, {J{\"o}rg Peter}",
    year = "2013",
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    language = "English",
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    Fabrication and bonding of thiol-ene-based microfluidic devices : Technical Note. / Sikanen, Tiina M; Lafleur, Josiane P.; Moilanen, Maria-Elisa; Zhuang, Guisheng; Jensen, Thomas Glasdam; Kutter, Jörg Peter.

    In: Journal of Micromechanics and Microengineering, Vol. 23, No. 3, 2013.

    Research output: Contribution to journalJournal articleResearchpeer-review

    TY - JOUR

    T1 - Fabrication and bonding of thiol-ene-based microfluidic devices

    T2 - Technical Note

    AU - Sikanen, Tiina M

    AU - Lafleur, Josiane P.

    AU - Moilanen, Maria-Elisa

    AU - Zhuang, Guisheng

    AU - Jensen, Thomas Glasdam

    AU - Kutter, Jörg Peter

    PY - 2013

    Y1 - 2013

    N2 - In this work, the bonding strength of microchips fabricated by thiol-ene free-radical polymerization was characterized in detail by varying the monomeric thiol/allyl composition from the stoichiometric ratio (1:1) up to 100% excess of thiol (2:1) or allyl (1:2) functional groups. Four different thiol-ene to thiol-ene bonding combinations were tested by bonding: (i) two stoichiometric layers, (ii) two layers bearing complementary excess of thiols and allyls, (iii) two layers both bearing excess of thiols, or (iv) two layers both bearing excess of allyls. The results showed that the stiffness of the cross-linked polymer plays the most crucial role regarding the bonding strength. The most rigid polymer layers were obtained by using the stoichiometric composition or an excess of allyls, and thus, the bonding combinations (i) and (iv) withstood the highest pressures (up to the cut-off value of 6 bar). On the other hand, excess of thiol monomers yielded more elastic polymer layers and thus decreased the pressure tolerance for bonding combinations (ii) and (iii). By using monomers with more thiol groups (e.g. tetrathiol versus trithiol), a higher cross-linking ratio, and thus, greater stiffness was obtained. Surface characterization by infrared spectroscopy confirmed that the changes in the monomeric thiol/allyl composition were also reflected in the surface chemistry. The flexibility of being able to bond different types of thiol-enes together allows for tuning of the surface chemistry to yield the desired properties for each application. Here, a capillary electrophoresis separation is performed to demonstrate the attractive properties of stoichiometric thiol-ene microchips.

    AB - In this work, the bonding strength of microchips fabricated by thiol-ene free-radical polymerization was characterized in detail by varying the monomeric thiol/allyl composition from the stoichiometric ratio (1:1) up to 100% excess of thiol (2:1) or allyl (1:2) functional groups. Four different thiol-ene to thiol-ene bonding combinations were tested by bonding: (i) two stoichiometric layers, (ii) two layers bearing complementary excess of thiols and allyls, (iii) two layers both bearing excess of thiols, or (iv) two layers both bearing excess of allyls. The results showed that the stiffness of the cross-linked polymer plays the most crucial role regarding the bonding strength. The most rigid polymer layers were obtained by using the stoichiometric composition or an excess of allyls, and thus, the bonding combinations (i) and (iv) withstood the highest pressures (up to the cut-off value of 6 bar). On the other hand, excess of thiol monomers yielded more elastic polymer layers and thus decreased the pressure tolerance for bonding combinations (ii) and (iii). By using monomers with more thiol groups (e.g. tetrathiol versus trithiol), a higher cross-linking ratio, and thus, greater stiffness was obtained. Surface characterization by infrared spectroscopy confirmed that the changes in the monomeric thiol/allyl composition were also reflected in the surface chemistry. The flexibility of being able to bond different types of thiol-enes together allows for tuning of the surface chemistry to yield the desired properties for each application. Here, a capillary electrophoresis separation is performed to demonstrate the attractive properties of stoichiometric thiol-ene microchips.

    U2 - 10.1088/0960-1317/23/3/037002

    DO - 10.1088/0960-1317/23/3/037002

    M3 - Journal article

    VL - 23

    JO - Journal of Micromechanics and Microengineering

    JF - Journal of Micromechanics and Microengineering

    SN - 0960-1317

    IS - 3

    ER -