The NCLA conducts a
wide range of laser materials processing applications at its laboratories based in
Galway. Please click on the links below to view a description of
the applications. |
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Cutting
Lasers are used in a vast range of cutting applications in activities as diverse as
shipbuilding and microsurgery. There are a number of important advantages to laser
cutting of materials over conventional means:
- Can machine most types of material including metals, polymers, wood, glass, ceramic
- Small kerf width to 20 microns
- High precision compared to plasma, flame, water-jet cutting
- Small cut taper
- Minimal Heat Affected Zone (HAZ)
- Minimal part tooling required
- Low running costs
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Figure: Map of Ireland laser cut from 0.5mm thick steel
Figure: Laser cut stainless steel stencil
Figure: Aperture laser cut from 0.5mm thick ceramic material
Figure: Metallurgical cross-section showing Recast later on laser cut component
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Drilling
Lasers are a useful tool for drilling holes into a wide range of materials. Hole
sizes down to 8 microns can be drilled and as it is a non-contact process there is no tool
wear or maintenance time required for the replacement of drill bits. High aspect
ratio holes can be drilled in hard materials for example for cooling channels in turbine
blades, for nozzles in ink-jet printers, or for via hole drilling on printed circuit
boards, as well as for a range of applications in the medical device sector. |
Figure: Laser drilled hole (~80um) in plastic medical device
Figure: Array of 10um diameter holes drilled in stainless steel using a femtosecond
laser
Figure: Cross-section of holes (see above) drilled in stainless steel using a
femtosecond laser
Figure: Holes drilled in an hypo tube using a pulsed Nd:YAG laser
Figure: 30 micron diameter holes drilled in medical device polymer
tubing using a DPSS laser.
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Welding
The ideal welding solution requires precise delivery of thermal energy to a well defined
location over a specific time interval. In many process lasers have been shown to
closely approximate this ideal solution. The NCLA has developed a particular
expertise in the laser welding of polymer materials for the medical device and packaging
industries. The development of laser welding processes for polymer materials can
lead to significant increase in factory automation and can reduce the amount of solvents
and adhesives required for the manufacturing process. |
Figure: Laser welded surgical component
Figure: Metallurgical cross-section of laser welded surgical component
Figure: Laser welding of an aeropspace component
Figure: Cross-section of laser welded aerospace component. Component welded
from both sides to achieve full penetration
Figure: Laser spot welded hypo-tube
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Marking, Engraving, and Etching |
Laser marking is used to induce a permanent
alteration to the surface of a material that is capable of resisting solvents and
abrasion. Laser marking has numerous advantages over alternative technologies including:
- High degree of permanence
- Clean
- Fast
- Programmable (computer controlled)
- Low consummable costs
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Figure: Laser marking of anodised aluminium
Figure: Various laser marked parts
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Micromachining |
| UV laser micro-machining is the application of short, intense
pulses of ultra-violet light to ablate or machine small amounts of material from the
surface of a sample. The technique is used for machining of fine, micron-sized features in
polymer materials, for micro-hole drilling, selective thin-film removal, surface
engineering and milling or 3-D micro-structuring. |
Figure: Holes drilled in a plastic part with an excimer laser
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| The NCLA facility features two excimer lasers, a high power
laser system and a compact short-pulse laser, which have the capability of operating at
either 193 nm or 248 nm. The lasers are integrated with a fully automated micro-machining
centre. The micro-machining centre consists of beam conditioning and steering optics, a
mask projection system and a vision and motion control system. These features allow
automated, continuously variable de-magnification, with integrated motion in x-y and theta
directions. The station also features a motorised catheter holder. System control is via
pc, with a dual-camera vision system, CAD/CAM interface and process optimisation software. |
Figure: Laser micromachining workstation at NCLA facility
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Video segment of Excimer laser machining holes in polymer
material
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Case Study:
Electrode
patterning for electronic and medical products
Selective ablation and surface roughening are two key processes in the
design and manufacture of electrodes for electronic and medical applications. Using
direct-write, or mask projection, custom patterns can be machined in small electrode
structures. The surface roughness of the device can also strongly influence its
performance, and UV laser pulses can be tailored to optimise the roughness of a material
for a given application. |
click to enlarge
(large file)
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Ultrafast Laser Materials Processing |
In association with the National Centre for
Biomedical Engineering Science, the NCLA has recently commissioned a
state-of-the-art Ultrafast laser materials processing facility based on a Clark MXR
femtosecond laser system. For further details please see our Ultrafast Materials processing page.
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Surface
Activation |
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ability to selectively alter the bio-response of a surface is important for future medical
devices and applications in nanotechnology. The surfaces of polymer materials are
investigated using an ArF (l = 193 nm) excimer laser and a monochromatic Xonen ((l = 172 nm) lamp. The biological responses to
the laser treated samples were studied using 3T3 fibroblast cells. As cells morphologically change on contact with a
surface in an effort to stabilise the cell material interface, the adhesion and spreading
of cells on the treated materials are
observed in comparison on cells cultured on non-treated materials. |
Figure: Water contact angle showing hydrophobic surface
Figure: Water contact angle showing hydrophilic surface
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| Laser Ablation |
The NCLA conducts a signicant
amount of research on laser ablation mechanisms using DPSS (355nm,
266nm) lasers and femtosecond lasers.
High speed imaging is a useful tool to gain an understanding of the
ablation mechanisms and the interactions with the material and the
ambient environment. |
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Figure: High speed false colour image
(2ns gate) of laser generated plasma plume. Picture taken ~50ns after
start of laser pulse.
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Figure: Shadowgraph
illustrating laser generated shockwave in ambient environment and
expulsion of molten debris (FOV ~300umx300um).
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Video
compilation of high speed images of laser plasma plume evolution
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Video compilation of debris expulsion of
laser interaction zone |
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