Polymer micromolds with near optical quality surface finishes

Autor: Pun-Pang Shiu, George K. Knopf, Suwas Nikumb
Rok vydání: 2012
Předmět:
Engineering drawing
Finishing
Diode-pumped solid-state laser
Manufacturing engineers
Microfluidics
Metallic masks
Surface finish
Pumping (laser)
Molds
Fabrication process
Surface properties
Demolding
Functional polymers
Composite material
Optical quality surfaces
Mold-Masters
chemistry.chemical_classification
Pressing
micromold
BioMEMS
Manufacture
Micro-feature
High quality surface
Polymer
Finite element method
Optical qualities
visual_art
visual_art.visual_art_medium
Curved microchannel
Microfeatures
Passive components
Focused beams
Environmental Monitoring
Materials science
Fabrication
Finite element models
Intrusion process
Polymer molds
Microsystems
Substrate (printing)
Contact less
Substrates
Non-contact
Micro-molds
FEM models
Microchannels
Stress-strain curves
chemistry
Micro fluidic system
Electronic component
Material temperature
Stress-strain relationships
Substrate material
Surface finishes
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.908098
Popis: Disposable microfluidic systems are used to avoid sample contamination in a variety of medical and environmental monitoring applications. A contactless hot intrusion (HI) process for fabricating reusable polymer micromolds with near "optical quality" surface finishes is described in this paper. A metallic hot intrusion mask with the desired microchannels and related passive components is first machined using a tightly focused beam from a diode-pumped solid-state (DPSS) laser. The polymer mold master is then created by pressing the 2D metallic mask onto a polymethylmethacrylate (PMMA) substrate. Since it is a contactless fabrication process the resultant 3D micro-reliefs have near optical quality surface finishes. Unfortunately, the desired micro-relief dimensions (height and width) are not easily related to the hot intrusion process parameters of pressure, temperature, and time exposure profile. A finite element model is introduced to assist the manufacturing engineer in predicting the behavior of the PMMA substrate material as it deforms under heat and pressure during micromold manufacture. The FEM model assumes that thermo-plastics like PMMA become "rubber like" when heated to a temperature slightly above the glass transition temperature. By controlling the material temperature and maintaining its malleable state, it is possible to use the stress-strain relationship to predict the profile dimensions of the imprinted microfeature. Examples of curved microchannels fabricated using PMMA mold masters are presented to illustrate the proposed methodology and verify the finite element model. In addition, the non-contact formation of the micro-reliefs simplifies the demolding process and helps to preserve the high quality surface finishes. © 2012 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
Microfluidics, BioMEMS, and Medical Microsystems X, January 23-24, 2012, San Francisco, CA, USA
Series: Proceedings of SPIE; no. 8251
Databáze: OpenAIRE
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