© Fraunhofer ILT

J. Gottmann, M. Hermans, J. Ortmann, www.lightfab.de N. Repiev, F. Riedel, I. Kelbassa, R. Poprawe RWTH Aachen Univ.

3D MICRO STRUCTURES IN GLASS BY ISLE WITH HIGH SPEED MICRO SCANNER

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3D MICRO STRUCTURES IN GLASS BY ISLE WITH HIGH SPEED MICRO SCANNER Motivation: Digital Photonic Production in Glass

ISLE-parts and Micro Scanner

Scalability

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Product complexity

Conventional Production

Lot size

Photonic

Production

Conventional Production

Innovative business models

Individualisation for free Individualisation for free Complexity for free

Innovative products

Cost Cost

Producer

Product

Providing-Value Value-Co-Creation

Producer Customer

Product

Environment

Photonic

Production

Digital Photonic Production – Vision

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Selective Laser-Induced Etching, “SLE”

fs laser radiation

v=1-10,000 mm/s

Wet etching

HF or KOH

Processing steps:

1) Selective modification of

the structure in the volume

by fs laser radiation

2) Selective wet chemical

etching of the modified

structure

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Experimental – Selective Etching

Etch rate of unmodified material r0 =0.21µm/h ± 0.015µm/h

Selectivity S: 𝑆 =𝑟𝑠+𝑟0

𝑟0 ; High Selectivity high aspect ratio

2 mm

l S~1400

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Motivation – What is Possible

By stacking single lines together SLE enables 3D-Microproduction of

Precise (blind) holes & grooves

Complex microfluidic devices

Already assembled micromechanics

in transparent materials like fused silica and sapphire

for applications like electrical vias, cell detection and sorting, filtering, drop making, fibre tip placement, injection nozzles etc.

Bellouard 2012 Matsuo 2008

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Digital Photonic Production with ISLE

3D-CAD Model

in Layers

Selective Modification

by Laser Radiation

Removal of Modified Material

by Wet Chemical Etching

ISLE: In-volume Selective Laser-induced Etching 1 mm

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Digital Photonic Production: CAD to CAM

CAD:

3D object in

common file type

Check for

closed volumes

Connection to

surface for etching

For CAM:

Definition of laser

tracks & layers

Automatic slicing

Check for artifacts

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Digital Photonic Production: CAM

CAM:

Alignment and process control with included microscope

Automatic control of translation stage, scanner and laser

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Digital Photonic Production: CAM & Process control

Automatic control of translation stage, scanner and laser

Alignment and process control with included microscope

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Digital Photonic Production: Resulting Microfluidics

3D microfluidic device after etching before separation

Transparency is increased when filled with water (immersion)

Diffraction at modified lines

before etching

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Digital Photonic Production: Resulting Microfluidics

3D microfluidic device after etching before separation

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Digital Photonic Production: 3D Mixer

3D microfluidics with glass-ball inside reaction chamber

2 mm

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DPP: Planetary drive with herringbone gearing

Planetary drive with herringbone gearing printed in fused silica

2 mm

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DPP: Laval Nozzle

Laval nozzle inset manufactured with SLE in fused silica

2 mm

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Micro Holes Cut in Fused Silica

Holes cut in 1 mm fused silica e.g. for

Optical Fiber placement

Filtering applications

Openings in casings

Inlets for gases or fluids

Electrical vias

Min. hole diameter ~ 30 µm

Max. hole diameter ~ 1 mm

Max. hole length ~ 2 mm

Max. hole taper ~ 20 µm

Precision ~ 2 µm

500 µm

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3D Microfluidic Device e.g. for Medical Diagnosis

3D micro channel in fused silica for characterization of living cells:

Buried flat channel

Tapered inlet

Connectors for flexible tubes

Prototypes and series from your CAD data

CAD data handling on request

Min. channel height ~30 µm

Min. channel width ~ 10 µm

Max. structure height ~ 2 mm

Max. structure width ~ 10 mm

1 mm

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3D Micro Mechanics e.g. for Micro Fluidics

3D micro mechanics in fused silica:

Free rotatable gear

Produced already mounted on axis

Available in buried micro channel

Prototypes and series from your CAD data

CAD data handling by us possible

Min. gap height ~20 µm

Min. gap width ~ 10 µm

Max. structure height ~ 2 mm

Max. structure width ~ 10 mm

1 mm

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Micro Scanner for Integration in Your System

Flexible Micro Scanner for your xyz stage system Designed for:

Research and application labs

1 µm focus radius (l~1µm), >0.2 m/s on 500 µm

Prototypes and small series of micro structures

Matched for Lasers with 0.1-5 MHz, 1-20 W

Properties

Scanning field 1 mm with lens f=10 mm

Reflected-light microscope included

CAM software, adapted to your system

Extendable with modules tailored for your needs

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High speed Micro Scanner for Volume Production

High speed micro scanner for high throughput:

1 µm focus radius (l~1µm), 10 m/s on 500 µm

Series of micro channels and holes

Matched for Lasers with 5-100 MHz, 20-150 W

Properties:

Scanning field 1 mm with lens f=10 mm

x-y stage and fast focusing included

Microscope & absorbed power meter included

CAM software

Tailored scanner for optimized throughput

500 µm

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Scope of Applications for Micro Scanners

Small focus (< 2 µm), high precision (< 1 µm) combined with large scanning velocity (0.1-10 m/s) are demanded in e.g.:

Micro structuring by ablation with high precision

Cutting of shaped holes

Crack free markings inside glasses

Fabrication of waveguides

Nanostructures (Ripples, Nanoplanes)

2 photon polymerization with high velocity

Structuring by ISLE

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OUTLINE

Motivation: Digital Photonic Production in Glass

ISLE-parts and Micro Scanner

Scalability by High Speed Micro Scanner

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ISLE with high average power laser (30 W) 8 mm long micro-channels in fused silica

Scanning velocity 10 m/s on 630 µm circles, Focus radius 1 µm, 0.5 & 5 ps

Repetition rate 27 MHz, Average power 10–30 W

Crack-free channels with 0.5 ps possible

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5 ps 24,3 W

0.5 ps 24,3 W

0.5 ps 16,2 W

630 µm

630 µm Scanning

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Drilling of Glass with High Speed Micro Scanner

Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:

Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz

Focus diameter: 2 µm

Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm

Track velocity: 3 m/s, Processing time per hole: 23 ms

Removal rate: 1.3 mm3/s resp. 0.17 mm3/Ws

27W 18W 8W 5.4W

400 µm

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Drilling of Glass with High Speed Micro Scanner

400 µm

Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:

Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz

Focus diameter: 2 µm

Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm

Track velocity: 3 m/s, Processing time per hole: 14 ms

Removal rate: 2.2 mm3/s resp. 0.28 mm3/Ws

34W 24W 8W 5.4W

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Drilling of Glass with High Speed Micro Scanner

400 µm

Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:

Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz

Focus diameter: 2 µm

Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm

Track velocity: 3 m/s, Processing time per hole: 9 ms

Removal rate: 3.5 mm3/s resp. 0.3 mm3/Ws

40W 30W 11.5W 5.4W

© Fraunhofer ILT

Drilling of Glass with High Speed Micro Scanner

400 µm

Drilling of 1 mm fused silica by ISLE with High Speed Micro Scanner:

Laser: Edgewave, 1064 nm, 10 ps, 80 W, 7 MHz

Focus diameter: 2 µm

Hole Diameter: 200 µm, Pitch: 400 µm, Depth: 1,000 µm

Track velocity: 3 m/s, Processing time per hole: 6 ms

Removal rate: 5.2 mm3/s resp. 0.45 mm3/Ws

40W 30W 11.5W 5.4W

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Summary

ISLE is suitable for Digital Photonic Production

ISLE is Scalable

3D Microfluidics and Assembled Micro Mechanics

Flexible Micro Scanner for Prototypes from CAD

High Speed Micro Scanner for high Throughput of e.g. Holes and Micro Channels

Spin-off LightFab for: Micro Scanners and Production of ISLE-parts

Acknowledgement:

Funding: NRW.Transfer Science-to-Business Pre-Seed to prepare the spin-off

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Outlook

Our Tasks:

First time right

Float glasses

Process control

Process chains

Needs:

Description of modification processes

Control of stress, crack prevention

Basis for selectivity: Defects or thermal history?

Fast dynamic diagnosis

Control of focus: time & phase & aberrations (PFT)