Rapid Fabrication of Round Flexdym Microchannels via Direct PDMS (Thermoset)-to-Flexdym (Thermoplastic) Thermal Replication
4 affiliations
- 1SMALL (Sensors and MicroActuators Learning Lab), Department of Electrical and Computer Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
- 2Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
- 3The Institute for Lasers, Photonics, and Biophotonics, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
- 4Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, NY 14260, USA
Abstract
Round microchannels provide physiologically relevant flow environments and improved fluidic performance compared with conventional rectangular geometries; however, their scalable fabrication in potentially biocompatible thermoplastic substrates remains challenging. Here, we present a rapid and low-cost PDMS-to-Flexdym thermal replication strategy to directly transform round microchannel architectures from a reusable compliant thermoset PDMS mold into a thermoplastic microfluidic platform. Round PDMS convex molds generated by thermal air expansion followed by PDMS double casting were used for heat-assisted conformal replication to transform spatially varying complex round microchannels into Flexdym. The method successfully transferred complex serpentine, branched, and interconnected channel architectures while preserving continuous flow paths and curved geometries. Temperature-dependent framework and experimentation revealed improved vertical feature recovery with increasing embossing temperature, while lateral dimensions remained highly conserved. Across representative channel widths of ~37–249 µm, replicated Flexdym channels achieved width and height transfer ratios of approximately 99–103% and 93–105%, respectively. Sequential dimensional analysis among concave PDMS, convex PDMS, and Flexdym replicas showed no statistically significant differences in channel width or height (p > 0.05), confirming high geometric fidelity throughout the replication process. AFM, SEM, and stylus profilometry results further verified the preservation of surface characteristics, rounded cross-sectional morphology, and reproducible channel profiles, with Flexdym surface roughness reduced from ~84.1 nm (PDMS mold) to ~25.1 nm in Flexdym after replication. Finally, integration of the replicated round channels into a multilayer microvalve demonstrated functional fluidic control through syringe-assisted compressed air actuation, supported by two-phase moving-mesh simulation and analytical air compression modeling. This strategy provides a practical route for translating PDMS-based round microchannel prototyping into scalable, more biocompatible thermoplastic microfluidic platforms for building next-generation microphysiological systems and bioengineering applications.
Related
- A Biobased Epoxy Resin with Sequential Thermoplastic-to-Thermoset Curing Enables Removable-to-Permanent Adhesive Bonding
- Controlled Growth of Architectured Boron Nitride Films by Chemical Vapor Deposition in Model Microchannels
- Raman Spectroscopy–Evolved Gas Analysis–Mass Spectrometry Provides Insight into Thermoset Thermal Degradation
- Spatially programmed MOF-coated microchannels for capillary-driven microvolume analysis
- Cross-Linking Simulation at Metal Oxide-Thermoset Interfaces Using Quantum Chemical and Molecular Dynamics Methods
BibTeX
@article{kabir2026rapid,
title = {{Rapid Fabrication of Round Flexdym Microchannels via Direct PDMS (Thermoset)-to-Flexdym (Thermoplastic) Thermal Replication}},
author = {Md Emamul Kabir and Sonali Garg and Aldrian Muhaxheri and Paras N. Prasad and Kwang W. Oh},
journal = {Polymers},
year = {2026},
month = sep,
doi = {10.3390/polym18192387},
url = {https://europepmc.org/article/PMC/PMC13667228},
note = {CC BY},
}
RIS
TY - JOUR
TI - Rapid Fabrication of Round Flexdym Microchannels via Direct PDMS (Thermoset)-to-Flexdym (Thermoplastic) Thermal Replication
AU - Md Emamul Kabir
AU - Sonali Garg
AU - Aldrian Muhaxheri
AU - Paras N. Prasad
AU - Kwang W. Oh
PY - 2026
DA - 2026/09/30
JO - Polymers
DO - 10.3390/polym18192387
UR - https://europepmc.org/article/PMC/PMC13667228
AB - Round microchannels provide physiologically relevant flow environments and improved fluidic performance compared with conventional rectangular geometries; however, their scalable fabrication in potentially biocompatible thermoplastic substrates remains challenging. Here, we present a rapid and low-cost PDMS-to-Flexdym thermal replication strategy to directly transform round microchannel architectures from a reusable compliant thermoset PDMS mold into a thermoplastic microfluidic platform. Round PDMS convex molds generated by thermal air expansion followed by PDMS double casting were used for heat-assisted conformal replication to transform spatially varying complex round microchannels into Flexdym. The method successfully transferred complex serpentine, branched, and interconnected channel architectures while preserving continuous flow paths and curved geometries. Temperature-dependent framework and experimentation revealed improved vertical feature recovery with increasing embossing temperature, while lateral dimensions remained highly conserved. Across representative channel widths of ~37–249 µm, replicated Flexdym channels achieved width and height transfer ratios of approximately 99–103% and 93–105%, respectively. Sequential dimensional analysis among concave PDMS, convex PDMS, and Flexdym replicas showed no statistically significant differences in channel width or height (p > 0.05), confirming high geometric fidelity throughout the replication process. AFM, SEM, and stylus profilometry results further verified the preservation of surface characteristics, rounded cross-sectional morphology, and reproducible channel profiles, with Flexdym surface roughness reduced from ~84.1 nm (PDMS mold) to ~25.1 nm in Flexdym after replication. Finally, integration of the replicated round channels into a multilayer microvalve demonstrated functional fluidic control through syringe-assisted compressed air actuation, supported by two-phase moving-mesh simulation and analytical air compression modeling. This strategy provides a practical route for translating PDMS-based round microchannel prototyping into scalable, more biocompatible thermoplastic microfluidic platforms for building next-generation microphysiological systems and bioengineering applications.
SN - 2073-4360
ER -