Assembly of Polymer Microfluidic Components and Modules: Validating Models of Passive Alignment Accuracy.
Byoung Hee You1, Daniel S Park2, Sudheer D Rani3
1Department of Engineering Technology and the Material Science, Engineering, and Commercialization Program, Texas State University, San Marcos, TX 78666 USA.
Journal of Microelectromechanical Systems : a Joint IEEE and ASME Publication on Microstructures, Microactuators, Microsensors, and Microsystems
|December 10, 2019
Summary
Low-cost modular polymer microfluidic devices utilize passive alignment for accurate assembly. This method enables predictable and feasible construction of advanced polymer microsystems for broader scientific applications.
Area of Science:
- Polymer microfluidics
- Microsystems engineering
- Mechanical engineering
Background:
- Modular polymer microfluidic platforms offer cost-effective solutions for molecular and environmental analyses.
- Accurate assembly of these microfluidic systems is crucial for reliable instrument function.
- Passive alignment presents a viable approach for achieving precise microfluidic device assembly.
Purpose of the Study:
- To investigate the accuracy of passive alignment in modular polymer microfluidic devices.
- To develop and validate an assembly tolerance model for predicting alignment accuracy.
- To assess the feasibility and predictability of assembling advanced polymer microsystems.
Main Methods:
- Replication of modular devices with passive alignment features (hemispherical pins in v-grooves) using double-sided injection molding in polycarbonate.
- Measurement of dimensions and locations of assembly features and integrated alignment standards.
- Application of an assembly tolerance model with Monte Carlo methods to predict assembly accuracy based on manufacturing variations.
Main Results:
- Measured assembly mismatches ranged from 16 ± 4 to 20 ± 6 µm (x-axis) and 103 ± 7 to 118 ± 11 µm (y-axis).
- Vertical variation from the nominal 287 µm was -10 ± 4 to 34 ± 7 µm.
- The assembly tolerance model accurately predicted experimental results, with 2%-13% differences attributed to unmodeled variations.
Conclusions:
- Accurate assembly of polymer microsystems using passive alignment is achievable.
- The developed assembly tolerance model provides predictable insights into assembly accuracy during the design phase.
- This research supports the broader application of low-cost modular microfluidic platforms.
