Facile Patterning of Thermoplastic Elastomers and Robust Bonding to Glass and Thermoplastics for Microfluidic Cell Culture and Organ-on-Chip
Abstract
:1. Introduction
- Thermal fusion bonding requires contact pressure and temperatures in the range of the glass transition temperature of the respective material. These working conditions are necessary for polymer chain fusion at the interface of the two substrates. The resulting bond is strongly dependent on well-optimized parameters for heat and pressure in order to achieve sufficient bonding strength without channel deformation [18].
- Solvent bonding is based on surface treatment with a suitable solvent to increase the mobility of polymer chains at the interface of the polymer substrates, resulting in a stable weld after complete evaporation [19]. However, excessive solvent exposure poses the risk of channel destruction and solvent residuals, which can be problematic for biological applications.
- Similarly, adhesive bonding can result in channel clogging due to excessive spreading of adhesives into microstructures and often needs to be addressed by optimized glue deposition e.g., by adhesive contact printing [20]. Furthermore, depending on the desired application, adhesives need to be chosen carefully with respect to bonding strength, material compatibility, absorption properties, and cytotoxicity [21].
2. Materials and Methods
2.1. SU-8 Microstructures
2.2. PDMS Mold Fabrication
2.3. Epoxy Master Mold Fabrication
2.4. Hot Embossing
2.5. TPE Bonding
2.6. Optical Characterization
2.7. Maximum Working Pressure Testing
2.8. Absorption Studies
2.9. Cell Culture Experiments
2.10. Live/Dead Staining
3. Results and Discussion
3.1. Patterning Process and Characterization
3.2. Device Bonding Strategies
3.3. (Bio)chemical Characterization
3.3.1. Small Molecule Absorption
3.3.2. Applicability for Cell Culture
4. Conclusions
Supplementary Materials
Author Contributions
Funding
Data Availability Statement
Conflicts of Interest
References
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Substrate | PDMS [Bar] | TPE (This Study) [Bar] | |
---|---|---|---|
PDMS | 2.9–6.7 | [41] | N/A |
TPE | N/A | 4.7 bar | |
Glass | 1.7–5.1 | [42] | >7.5 bar |
PC | 3.8 | [43] | >7.5 bar |
4.1 | [44] | ||
COC | >8 | [45] | >7.5 bar |
PS | 4.5 | [43,44] | >7.5 bar |
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Schneider, S.; Brás, E.J.S.; Schneider, O.; Schlünder, K.; Loskill, P. Facile Patterning of Thermoplastic Elastomers and Robust Bonding to Glass and Thermoplastics for Microfluidic Cell Culture and Organ-on-Chip. Micromachines 2021, 12, 575. https://doi.org/10.3390/mi12050575
Schneider S, Brás EJS, Schneider O, Schlünder K, Loskill P. Facile Patterning of Thermoplastic Elastomers and Robust Bonding to Glass and Thermoplastics for Microfluidic Cell Culture and Organ-on-Chip. Micromachines. 2021; 12(5):575. https://doi.org/10.3390/mi12050575
Chicago/Turabian StyleSchneider, Stefan, Eduardo J. S. Brás, Oliver Schneider, Katharina Schlünder, and Peter Loskill. 2021. "Facile Patterning of Thermoplastic Elastomers and Robust Bonding to Glass and Thermoplastics for Microfluidic Cell Culture and Organ-on-Chip" Micromachines 12, no. 5: 575. https://doi.org/10.3390/mi12050575