Microfluidics

Laser Processing for Microfluidics

Microfluidic devices can be produced with many construction methods—engraved channels in rigid plastics, laminated “stack-ups” built from films and adhesives, soft valves and membranes, and integrated filters. Laser processing supports fast iteration, tight geometry, and reliable alignment across these approaches, especially when designs change frequently or when tooling is slow and expensive.

Quick Answer (At-a-glance)

Best-fit operations (typical)

• Cutting microfluidic channel layers (films and laminates): strong fit
• Kiss-cutting PSA layers (cut layer(s) while preserving a liner/substrate): strong fit
• Cutting rigid substrates (PMMA/acrylic, some COC): strong fit (edge goals matter)
• Engraving controlled-depth channels in rigid plastics: strong fit (material dependent)
• Cut-to-print alignment and feature registration: strong fit with defined fiducials/workflow
• Cutting flexible membranes and soft materials: strong fit (material dependent)
• Cutting mesh filters and porous layers: strong fit

ULS helps you optimize

• Feature fidelity (small channels and tight radii) with appropriate optics and workflow
• Cleanliness and reduced re-deposition using airflow management + masking strategies
• Flatness and stability for thin films/laminates (tacky mats, vacuum tables, paper masking for downdraft)
• Accuracy through kerf compensation and (when needed) camera registration

What we’ll ask you for (to move fast)

• Your construction method (rigid engraved, stack-up laminate, tape/diagnostic film, PDMS/membrane, mesh filter)
• Materials and thicknesses for each layer (including liners/adhesives)
• Critical features (channel width, reservoir diameter, via/opening size) and tolerance priorities
• DXF (preferred) and any alignment marks/fiducials

Common Microfluidic Construction Methods (Choose your approach)

Rigid substrates (PMMA/acrylic, COC) — cut + engrave channels

Rigid substrates are often used for structural layers and channel layers. Laser processing enables rapid prototyping, smooth profiles, and repeatable features. Cleanliness and edge quality improve with airflow management, masking, and table selection.

Typical operations

• Through-cut outer perimeter and ports
• Engrave channels to controlled depths (material dependent)
• Create alignment holes and fastener holes

Lamination “stack-up” devices (PSA spacers, PET carriers, liners)

Stack-up devices are built from multiple layers—PET films, PSA adhesives, liners, and spacer laminates. Laser processing supports both through-cut and kiss-cut processes, enabling channels, vias, gaskets, and alignment features without hard tooling.

Typical operations

• Cut spacer layers that define channel height
• Kiss-cut adhesive layers while preserving a liner/substrate
• Produce alignment holes and registration features

Adhesive microfluidic tapes and diagnostic films (kiss-cut + through-cut)

Microfluidic tapes combine films + liners + adhesives. Kiss-cut and through-cut processes can be used to create channel patterns and shapes while preserving liners.

Typical operations

• Kiss-cut coils/channels while preserving liner
• Through-cut outlines, ports, and windows
• Keep edges clean using the right lens + airflow

Soft materials (PDMS, thin membranes) — valves and seals

Soft layers (PDMS sheets, TPU-like membranes, silicone adhesives) are used for valves, seals, and compliant interfaces. Laser processing can cut these layers with controlled geometry when fixturing and airflow are aligned to the material.

Filters & porous layers (PET mesh)

Mesh layers are used as filters and membranes. Laser processing can cut and mark mesh structures and produce repeatable discs and openings; optical configuration is selected to balance feature fidelity with efficient processing.

ULS Solutions That Improve Microfluidics Results

Optics for fine features

• HPDFO / high power density optics help achieve very small spot size for fine channels and microfeatures.
• Selectable power density (e.g., 4X vs 13X) allows tuning spot size and focal tolerance to match thickness and feature goals.

Air/Gas Assist & airflow management

• Coaxial and lateral/back-sweep assist options help move debris and gas-phase byproducts away from the cut, improve cleanliness, and protect optics.
• Downdraft / honeycomb tables, pin tables, and stand-off pins help reduce flashback and improve back-side quality for rigid sheets.

Masking as a cleanliness lever

• Masking films/paper liners/transfer tape can capture dross and prevent re-deposition on functional surfaces.
• Masking the table area around thin films can increase effective vacuum hold-down and improve flatness.

Repeatability

• Stable fixturing + consistent job workflow drives repeatability across batches and helps maintain accuracy for microchannel features.

Precision, Tolerances & Registration

Microfluidic devices often require tight positional accuracy for ports, channels, and alignment holes.

Key levers

• Flatness and stability of the layer (tacky mat / vacuum / masked downdraft)
• Kerf compensation for tolerance-critical edges and holes
• Camera registration with fiducials for print-to-cut alignment and array production

Fiducials (when alignment matters)

• Fiducials should have high contrast, a clearly defined center, and sufficient size.
• Keep the area around fiducials visually consistent (avoid logos/printing in the camera view).

Cleanliness, Debris, and Edge Quality

Clean edges and low debris are essential for bonding/lamination and for reliable fluid behavior. ULS combines airflow + masking + process strategy to keep features clean and consistent. When needed, light wiping with compatible solvents can remove residual debris.

Fixturing & Flatness (thin films and stacked laminates)

Thin layers and adhesives need stability.

Common stability strategies

• Tacky mats for thin films/laminates
• Vacuum booster and honeycomb/downdraft tables
• Weights or perimeter restraint when appropriate
• Paper masking on tables to improve downdraft suction and protect back surfaces

Workflow (CAD → part, DXF/PDF import, repeatability)

• DXF is preferred for vector geometry.
• PDF import can support mixed vector and raster workflows.
• Use hairline vector paths for cut geometry and keep file versions organized.

Safety & Exhaust / Filtration Considerations

Laser processing polymers produces gaseous exhaust and particulates. Use appropriate extraction/filtration and follow facility EHS guidance. Effective airflow also improves edge cleanliness and repeatability.

Microfluidics FAQ (Engineer-focused)

Construction method selection

Q: What’s the best laser-friendly construction method for microfluidics?
A: It depends on your goals. Rigid substrates (PMMA/acrylic, some COC) are great for structural/channel layers and rapid prototyping. Stack-ups (PET + adhesives + liners) excel when you need scalable lamination and repeatable channel heights. Soft layers (PDMS/membranes) support valves and seals.

Q: Can you mix construction methods (rigid + stack-up + membrane)?
A: Yes—hybrid microfluidic devices are common. The key is defining which layers are cut, engraved, kiss-cut, or selectively processed, and then validating bonding/lamination steps.

Precision & tolerances

Q: What tolerances can you hold on microfluidic features?
A: Tight, repeatable positional accuracy is achievable when layers are held flat and the workflow is consistent. Tell us your tolerance bands and inspection method (optical/CMM/functional) so we can align the approach.

Q: How do you hit tight tolerances on thin films and laminates?
A: Flatness/stability first, then kerf compensation for tolerance-critical edges/holes. For high-volume arrays, shared-vector strategies and repeatable fixturing improve consistency.

Q: How do you align multiple layers in a stack-up?
A: Use alignment holes/pinholes and a consistent workflow. If you must align to printed/etched features, use camera registration and well-designed fiducials.

Kiss cutting & liners

Q: What is kiss cutting and why is it useful for microfluidics?
A: Kiss cutting cuts through one or more top layers (film/adhesive) while preserving a liner/substrate. It’s ideal for creating channels, gaskets, and adhesive patterns in stack-up devices.

Q: How do you preserve liners during kiss cutting?
A: Use an approach optimized for liner preservation, along with appropriate airflow/assist strategies and stable flatness.

Cleanliness & edge quality

Q: How do you reduce debris and re-deposition in microchannels?
A: Airflow management (coaxial or lateral/back-sweep) moves byproducts toward exhaust. Masking can capture deposition before it reaches critical surfaces.

Q: Do parts require post-cleaning?
A: Often minimal. Many designs are ready after masking removal; some materials benefit from a light solvent wipe depending on cleanliness requirements.

Registration & camera workflows

Q: When should I use camera registration?
A: Use it when you need cut-to-print alignment, when parts are pre-trimmed, or when you are producing arrays where placement variation must be corrected.

Q: What makes a good fiducial?
A: High contrast, an easily identifiable center point, and enough size for the camera field of view. Keep the background around the fiducial visually consistent.

Safety

Q: Do microfluidic materials generate fumes during laser processing?
A: Yes—polymers generate exhaust and particulates. Use appropriate extraction/filtration and follow EHS guidance.

Discuss Your Application with an Engineer

We don’t publish universal recipes because microfluidic devices vary widely by material, layer stack, and acceptance criteria. If you share your design and priorities, we can recommend the best approach.

Suggested form fields

• Construction method (rigid engraved, stack-up laminate, tape/diagnostic film, membrane/PDMS, mesh filter)
• Layer list (material + thickness for each layer, including liners/adhesives)
• Critical feature sizes (channels, vias, reservoirs) + tolerance priorities
• DXF upload + notes
• Contact info

Glossary & Synonyms (for AI/search matching)

• Microfluidic channels, reservoirs, mixing chambers, ports, vias
• Stack-up microfluidics, laminated microfluidics, PSA spacers
• Kiss-cut, through-cut, liner preservation
• PMMA/acrylic, COC/COC laminates, PET films/liners, PDMS, mesh filters
• Fiducials, camera registration, kerf compensation