INTRO
Lasertechnology: From bio-medical application to high-precision machines12 ways nano-patterns can make great improvements
Regarded as a side effect of laser technology for decades, they are increasingly in the spotlight:
Laser-induced periodic surface structures (LIPSS)
These microscopic patterns can form on the surface of almost any material when irradiating it with ultra-short laser pulses.
Versatile structures can be created
by varying, for instance, wavelength and pulse duration to generate
functionalised surfaces with different properties.
LIPSS possess great application potential in many industries including the biomedical and energy sectors. Keep scrolling to learn more about 12 uses of LIPSS you had never imagined!
LIPSS possess great application potential in many industries including the biomedical and energy sectors. Keep scrolling to learn more about 12 uses of LIPSS you had never imagined!
10 uses of LIPSS
#1 LIPSS for anti-wettingLotus effect mimickry
The well-known Lotus effect is
created by nano-scopic structures on the leaves' surface.
These structures can be generated through ultra-short laser pulses to mimick the anti-wetting properties on glass or metallic surfaces for self-cleaning windows and windshields or to reduce corrosion and stiction in machinery.
These structures can be generated through ultra-short laser pulses to mimick the anti-wetting properties on glass or metallic surfaces for self-cleaning windows and windshields or to reduce corrosion and stiction in machinery.
#2 LIPSS for anti-icing surfacesProper functioning of aircraft at freezing temperatures
Icing is a problem for aircrafts.
Their wings, propellers and other mechanical parts can be impaired by freezing
water droplets.
Inspired by the self-cleaning properties of the
Lotus plant, researchers from Dresden University of Technology and Airbus Central Research and Technology combine LIPSS and other nano-structures to create water repellent
surfaces. This will make de-icing a thing of the past.
#3 LIPSS to create anti-fingerprint surfacesSpotless touch application
Self-cleaning surfaces are attracting attention
from other areas, too. They can help to retain the shiny look of touch screens,
automotive parts or optical lenses.
For this to work, so-called amphiphobic surfaces must be created, for instance, through LIPSS. Such surfaces then repel both water and skin oil, the two main components of fingerprints.
For this to work, so-called amphiphobic surfaces must be created, for instance, through LIPSS. Such surfaces then repel both water and skin oil, the two main components of fingerprints.
#4 LIPSS for improved blood oxygenationPrevention of clogging in heart-lung machines
LIPSS generated amphiphobic surfaces could also find application in extracorporal membrane oxygenators. These medical machines circulate a patient's blood removing the carbon dioxide and oxygenizing it. An amphiphobic layer on the membrane can prevent blood cells from clogging it and hence device failure.
#5 Anti-bacterial surfacesLIPSS to repel bacteria
As far as theory goes, the strength with
which bacteria adhere to surfaces grows with the available surface area. Taking
that idea further: Nano-structures such as LIPSS can limit contact points for
microbes and hence their ability to proliferate.
In practice, it is challenging to get all the conditions just right for that to happen and not the opposite. However, initial research shows the potential of ultra-short pulsed laser technology to create antibacterial surfaces.
In practice, it is challenging to get all the conditions just right for that to happen and not the opposite. However, initial research shows the potential of ultra-short pulsed laser technology to create antibacterial surfaces.
#6 LIPSS on medical implantsFaster recovery and extended implant life
The healing process after receiving a prosthetics
pin depends on its surface characteristics and how the surrounding tissue responds
to it.
Hence, LIPSS do not only inhibit cell attachment but also foster it; it all depends on the surface
pattern.
The multi-laser beam module developed by Laser4surf creates functionalised surfaces to facilitate exactly that:
Quicker and better attachment of cell tissue to the implant for faster recovery.
The multi-laser beam module developed by Laser4surf creates functionalised surfaces to facilitate exactly that:
Quicker and better attachment of cell tissue to the implant for faster recovery.
#7 LIPSS in Li-ion batteriesExtending the lifetime of Li-ion batteries
Every Li-ion battery has a current collector on
either end:
One copper coated, the anode, and one aluminium coated, the cathode. They store the lithium ions and release them during battery operation for electricity to flow.
One copper coated, the anode, and one aluminium coated, the cathode. They store the lithium ions and release them during battery operation for electricity to flow.
Through laser engraved LIPSS on their surface, the current collectors can store more Li-ions, which
results in an increased electricity flow. These modifications also prevent battery
overheating and increase the battery life cycle by up to 30%.
Additionally, laser engraving circumvents expensive carbon coating methods and harmful etching processes, which are applied during the manufacturing of current collectors.
Additionally, laser engraving circumvents expensive carbon coating methods and harmful etching processes, which are applied during the manufacturing of current collectors.
#8 Light bulbs and LEDsLIPSS to brighten up lamps
The surface of a light bulb’s incandescent filament
can be increased through LIPSS. With a greater surface area, the filament
absorbs more energy and thus emits more light.
Scientists have also demonstrated that LIPSS can increase the power output of Gallium-nitride-based LEDs by 30%; which are diodes used in displays and traffic lights.
Scientists have also demonstrated that LIPSS can increase the power output of Gallium-nitride-based LEDs by 30%; which are diodes used in displays and traffic lights.
#9 LIPSS for next generation solar cellsHarnessing solar energy more efficiently
Thin-film
silicon solar cells can be mounted on
non-planar surfaces of vehicles or on the canvas of boats and tents. Their light
weight and flexibility allow more freedom in installation than conventional
photovoltaic modules but they are less efficient. Surface structures such as
LIPSS on their component layers can enhance their efficacy in two ways.
Light incoupling: LIPSS ensure more light enters the module.
Light trapping: The captured light stays in the cell for longer.
Light incoupling: LIPSS ensure more light enters the module.
Light trapping: The captured light stays in the cell for longer.
#10 LIPSS for structural colourationCreation of vibrant colours
Not pigments, but microscopic surface structures
give butterfly wings their bright, iridescent colours. This so-called
structural colour is a physical phenomenon created through reflection of
specific wavelengths. Structural colour does not experience bleaching and can
shift in hue or fade with changing position.
Structural colour on a stainless steel surface.
The colours are created by periodic, microscopic patterns engraved on the surface through laser texturing. By varying the period of the nano-structures, the textured surface reflects different wavelengths and produces different colours. This can be achieved with LIPSS too.
The colours change in hue with the viewing angle when the spacing between the ripples is constant (a) and they appear homogenous when ripples vary in period spacing (b). However, when mixing different variable period spacings, light is reflected non-specifically and appears white (c).
#11 LIPSS for anti-reflectionEssential parts of PCR machines: Optoelectronic devices
LIPSS can also be used to create surfaces that reflect no light at all.
This helps to improve optoelectronic devices which convert light into energy or
electronic data, or vice versa. Such devices find application in
telecommunication and medical equipment like PCR machines made famous by the COVID-19 test. During the PCR, optoelectronic devices detect the light impulses emitted from „DNA reading“ and convert them into DNA sequence information.
Qualitative anti-reflective surfaces ensure better transmission and contrast of the light signal and hence play an important role for the performance of optoelectronic devices.
Qualitative anti-reflective surfaces ensure better transmission and contrast of the light signal and hence play an important role for the performance of optoelectronic devices.
#12 LIPSS in linear encodersTuning measurement accuracy
LIPSS can improve other high precision machines
such as linear encoders. These measurement devices provide position information
to a mind-boggling array of applications. They ensure accurate positioning of
antennas for the aerospace industry, and help to assemble automotive parts
during automated manufacturing with precision.
Scientists from the Laser4surf project introduce LIPSS onto the encoder's scale to obtain a finer grid. Compared to conventional devices, the light signal reflected onto the detector is sharper and higher in contrast.
This enhances the encoder's precision and makes the device less sensitive to disturbances, like vibrations.
The all-in-one machineThe Laser4surf prototype
All these innovative applications require different processing parameters to generate the desired, unique pattern. Additionally, texturing surfaces at sub-micron level is time-consuming and expensive. Laser4Surf seeks to overcome this and bring laser texturing to mass production. The researchers and engineers will design a single machine to carry out all the necessary production steps: defining the required parameters, processing the surface and inspecting the product.
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12 ways nano-patterns can make great improvements
VIDEO Laserstructuring explained
Lotus effect mimickry
Proper functioning of aircraft at freezing temperatures
Spotless touch application
Prevention of clogging in heart-lung machines
LIPSS to repel bacteria
Faster recovery and extended implant life
Extending the lifetime of Li-ion batteries
LIPSS to brighten up lamps
Harnessing solar energy more efficiently
Creation of vibrant colours
Essential parts of PCR machines: Optoelectronic devices
Tuning measurement accuracy
The Laser4surf prototype
Laser4surf