What cool things you can do with Direct Laser Writing (a.k.a 3D printer)?

I am not talking about the cheap $500 material jetting/extrusion based 3D Printer nor the $5,000 Vat Photopolymerzation technique based steoreolithagraphy (http://3dprinting.com/what-is-3d-printing/). Here I am talking about the $500K 3D laser direct laser writing machine  that is wide used for micro-structure fabrication. In this technology, fs pulsed laser is tightly focus on the photosensitive resin and the tiny exposed area undergo  es two photons polymerization (TPP) and by moving this focused spot, one can create 3D structures in the submicron size.  I was lucky enough to involve several projects that fabricate structures using the Nanoscribe machine.

Alumina infiltrated octohedral structure
alumina-polymer_octohedral

Now back to the topic- what can you do with such a sophisticate machine ?

1. Rapid prototyping- in the micron scale. Previously, such a system has been used only in research laboratories since the process is quite time consuming. 100mm2 structure would normally take several days.  The latest  model utilizes high speed galvo mirrors and increases the speed by at least ten folds.

tajneedle
source: Nanoscribe

2. 3D Photonic Structures

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Left: 3D Photonic Crystals; Right: Gold helix metamaterial

3. Micromachine (Magnetic Sperm)

A research group at ETH Zurich successfully fabricated sperm shaped microrobots and control them using magnetic field.

4. Photonics Phase arrays / Optical filter

Researches at TU Hamburg has demonstrated that it is possible to create diffractive optics element using 3D printing technique. The waveguide based phase arrays allow user to encode their message into the structure and projected it later using the appropriate laser. The potential application is the anti-counterfeiting.

hologram
source: TUHH

5. Mechanical structures with nano/micro- lattices.

Several groups are currently investigating how the material + structures (lattice) influence the mechanical properties of the hierarchical structure.

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source: CALTECH

6. Medical applications

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Left:Polymer scaffold for cell culture; Right: Microneedless

Laser + Robotor for Coating Removal

Screen Shot 2016-02-01 at 9.50.57 PMSource: http://www.nrec.ri.cmu.edu/projects/ctc/

The aircraft inspection or service routinely involves the process of paint removal, inspection and repainting.  Coating removal operations are tedious and usually involve chemical and mechanical processes that result in significant emissions of volatile organic compounds, organic and inorganic hazardous air pollutants, and hazardous waste.

Laser Coating removal is paint stripping solution for all types of commercial and military aircraft & helicopters. LCR is by far the most superior solution among the current and future (planned) methods for ‘stripping/de-painting’ of commercial and military aircraft / helicopters.

According the cost assessment from Department of Defense ( DoD), such a Robotic Laser Coating Removal System (RLCRS) implementation results in a labor savings of approximately $7.4 million, an annual materials cost savings of approximately $113,600, and a waste management cost avoidance of approximately $60,000. The total annual operating cost savings equals approximately $7.5 million. A life-cycle cost analysis demonstrated that implementation and use of the RLCRS for coating removal of the targeted KC-135 parts would result in 15-year life-cycle cost savings greater than $111 million. These cost savings translate into a payback period of approximately 0.3 years.

Other Air Force depots and DoD facilities that perform chemical depainting of large off-aircraft parts will also realize similar cost savings. For example, if similar cost savings were assumed at all three of the major Air Force depots that perform chemical depainting operations on aircraft parts, the combined cost estimates would result in labor savings of approximately $66.6 million, an annual materials cost savings of approximately $1 million, and an annual waste management cost avoidance of approximately $540,000. The total annual operating cost avoidance would result in approximately $67 million per year for the U.S. Air Force.

A Dutch STRATAGEM Group (www.stratagemgroup.nl) has also developed the similar technology for the coating removal application.

The LCR laser uses a scalable 12-35 kW CO2 laser that can handle all paint colors. The laser evaporates and combusts the paint, while this paint effluent is immediately vacuumed from the surface and passed through the filtration system. The system has a built-in, closed-loop, color recognition and control system allowing it to strip both metal and composite surfaces in a very accurate way and make “selective stripping” possible. The laser is mounted on a 10 DOF robotic arm and mobile platform and is controlled by specifically designed software loaded in the LCR computer that has the capability to perform a geometric-robot path analysis of the aircraft. This allows the LCR to follow the three-dimensional contour of the aircraft in an optimal trajectory. For safety, a forward scanner is mounted on the robot end-effector to check the aircraft geometry in real-time. The system will be available in 4 sizes, the smallest for small aircraft such as fighter jets and helicopters, the largest for the A380. The system is fully autonomous and will be controlled by a single operator from behind a glass window separated supervisory room. The CO2 laser can remove the paint from the aircraft without damaging the metal or composite surface and will be fully compliant to the SAE MA4872A standard for thermal stripping as early tests in 2012 already showed. Furthermore, the LCR robot will comply with all safety requirements for labor and aircraft.

Source : DOD; http://www.nrec.ri.cmu.edu/projects/ctc/; http://www.mowarped.com/lcr/the-products/

3D Printing of plastic is so 1980s – Metals 3D printing is the real deal

3D printing of plastics has been around since the early of 1980s. It has it place in the prototyping and eduction, but not really in has an real industrial application. 3D printing of metal, on the other hand, allow to be used to manufacture final products in different industries, including aerospace, automotive, medical industries etc.

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source: EDAG: #btw, it is not a sculpture

According to the IDTEchEx report, metals are the fastest growing segment of 3D printing, with the machine sales growing at 48% in 2015 and material sales growing at 32%.

  • GE Aviation is investing $ 3.5B in EOS 3D printers to print 100K fuel nozzles by 2020.
  • Arcam said their printings have been used to manufacturer more than 50K medical implants using titanium alloy.
  • Siemens are producing turbine blades for power generation.
  • NASA said that they will use 3D printing to manufacturer 80 -100% of the rocket engines in the future.
  • rolls-Royce has announced that it will flight-test what it claims to be the largest 3D printed aerospace component to ever power an aircraft.

So who is the big player in this technology?  Currently the leading integrator/ suppliers in the metal 3D printing includes EOS, 3D Systems, Concept laser, Wuhan Binhu and Arcam, which all have shown significant growth over time.

metalpart2

3D printing technology is active in healthcare as well. According to the IndustrARC report, the global 3D printing in healthcare was approx. $ 487 million in 2014 and it is expect to grow over $3.89 Billion by 2022 ( including implants & dentals).

So who is using the 3D printing?

3d.printing.growth.chart_.1x519_0

source: MIT Technology Review, IDTechEx

Ever heard of CFRP?

CFRPs or CARBON FIBER REINFORCED PLASTICAs are increasing popular and a very interesting materials. It is getting a lots of attention especially in the automotive, aviation and wind power industries. For example, the Life module of the BMW i3 is made primarily of   this material. It is lighter than aluminum and  it is as strong as steel. It is our next gen. advanced material.

Passenger-compartment-bwm-i3

Seems to be an idea material-  so what is the problem ? The problem is that these two materials behave completely differently in the machining process: a mechanical cutter can pass through polymer like a knife through butter, but it will still blunt its edge on the hard fibers.That poses a problem for all mechanical processing methods. Water jet cutting with abrasive substances is far from ideal since the fibrous cut edge can easily be damaged by abrasive particles and fibers may become detached from the matrix as the material takes in moisture. Cutting imposes significant forces on the workpiece, which often results in rough cut edges with protruding fibers.

Machine tools pose the same kind of risk, though the main disadvantage here is the high cost of processing the workpieces. The hard fibers quickly wear down the drilling and milling heads so that they must be replaced multiple times each shift. In addition, any change in the thickness or composition of the material being machined generally means switching tools. This retooling process takes time, and constantly purchasing new tools is an extremely expensive business. Guaranteeing consistently high standards of production quality under these conditions also requires constant monitoring, which is yet another cost factor.

Solution? Laser Cutting!

Laser beams do not exert any mechanical forces on the workpiece. That makes them a good choice for machining very thin or delicate CFRP parts with great precision. A beam of light can be flexibly tailored to changing contours and geometries because the machining optics make no contact with the workpiece – in fact they are more than 150 millimeters away from it. That makes it easier for lasers to get into tight corners.

Das Licht eines Festkörperlasers koppelt hervorragend in die Kohlefasern ein: Die perfekte Schnittkante bei diesem CF-Preform ohne überstehende Fasern erleichtert und beschleunigt das anschließende Handling. Foto | TRUMPF

The light from a solid-state laser couples easily into carbon fibers. That gives CF preforms a perfect cut edge without protruding fibers, making subsequent handling faster and simpler. Photo | TRUMPF

Laser cutting of carbon fibers (CFs) and carbon fiber-reinforced plastics involves a sublimation process, which means that the material is vaporized as soon as it is hit by the accurate, high energy beam. That means there is no molten material to be ejected and the resulting edge is smooth, with no fibers protruding from it. The heat-affected zone at the cut edge is minimal and – according to findings so far – has no impact on the mechanical properties of the part

source: TRUMPF laser community

Just how much is Laser involve in Smartphones / Tablets Fabrication

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We are now living in the digital era. Almost everyone can’t live without smartphones or tablets. Barely 8 years ago, one family has max. 1 PC and 1 laptop. Now,  each family members have at least 1 smartphone and/or a tablet.

smartphone-case-ceramics-titanium-carbon-fibre-laser

The smartphones/tablets industry is really competitive nowadays. China, Korea, Japan and USA want to piece of the pie. In order to be successful, they should have the ability to constantly bring out new features, and manufacturing processes that are ever more efficient and less expensive. This is where the laser plays an important role.

  1. Sapphire cutting: Sapphire, the second hardest material in the world. It is an ideal material for the screen or a special cover to protect the camera. Typical mechanical processing and polishing are used in the watch industry for the sapphire shaping or processing. However, it is not fast enough to cope with the demands. So the manufacturers go for lasers instead. Using ultrashort pulsed laser, it is possible to cut the sapphire quickly, precisely and without the need of reworking.
  2. Cutting and drilling of flex film circuits: Laser is used to perform free form cutting of the polyimide film. Many thousands of tiny, conductor-filled holes connect the conductive tracks in the various layers (microvias). And increasingly, these holes are being drilled using infrared picosecond lasers, which can punch thousands of holes per second while making contact with the conductive tracks (no thicker than a human hair) with an accuracy of within ten micrometers. Normally mechanical drilling is used in this process. However, this method becomes increasingly expensive as hole diameters drop below 250 microslaser-flexible-film-circuit-cutting-interconnect
  3. OLED display processing: Lasers are also the way forward for the screens of the future. Flexible OLED screens are the stuff of dreams for product de-signers and production engineers. Mounting organic light-emitting diodes on plastic films means that displays can be shaped, curved and flexible.  At the same time, flexible displays would make roll-to-roll manufacturing techniques a real possibility. They would simply be wound off and on, passing through various printing and coating machines as part of continuous processes before, for example, being cut into displays of all sizes by a laser beam in a final step.OLED screens currently start life as a thin, liquid polyimide layer on a glass substrate. The polyimide hardens and forms the base film. Silicone layers are then applied for the transistors, onto which the actual OLEDs are then applied as screen pixels. To keep costs down, the silicone is applied in an amorphous layer and melted using a UV laser. During solidification the silicon crystallizes, which increases its conductivity and allows the transistors to switch faster, creating smoother images. laser-lift-off-oled-display-solid-state-laser-960x405
  4. Increasingly, lasers are being used to make the OLEDs themselves — at least indirectly. Display manufacturers produce OLED pixels using metal templates that are a little larger than a sheet of letter paper but just 30 microns thick and exhibiting a series of regularly arranged, tiny holes. The OLEDs are plotted through these holes as pixels 30 square micrometers in size. Because the extremely fine holes clog quickly, the metal template soon wears out and has to be replaced.
  5. Touchscreen patterning:Smartphone touchscreens usually consist of a thin film of transparent conductive oxide (TCO). These films are scribed to create the required pattern of electrically isolated electrodes and interconnects. This is typically accomplished using either wet chemical photoetching, or direct ablation of the TCO using a q-switched DPSS laser operating either in the infrared or green. However, emerging applications, particularly for AMOLED displays, are now putting higher demands on scribe quality beyond just electrical isolation, which in turn requires a more detailed examination of scribe geometry and hence quality. With q-switched lasers, which have pulsewidths in the nanosecond regime, there is sufficient time for laser induced heat to flow out of the localized laser interaction zone and cause peripheral thermal effects. Since the laser focal spot is on the micron scale, the time for this heat flow is on the order of 10 ps or more. This means that with a laser pulsewidth of 10 ps or less, material removal can carry away most of the laser pulse energy, before there is time for thermal energy out-flow.

Source: Trumpf Laser Community & Coherent- Onboard technology

 

Create a Waterproof and Ultra-black Metal using Laser surface structuring

Scientists at the University of Rochester have used lasers to transform metals into extremely water repellent, or super-hydrophobic, materials without the need for temporary coatings.

University of Rochester Institute of Optics professor Chunlei Guo has developed a technique that uses lasers to render materials hydrophobic, illustrated in these images taken in his lab December 19, 2013.  // photo by J. Adam Fenster / University of Rochester
University of Rochester Institute of Optics professor Chunlei Guo has developed a technique that uses lasers to render materials hydrophobic, illustrated in these images taken in his lab December 19, 2013. // photo by J. Adam Fenster / University of Rochester

Typically the water repellent properties uses chemical coatings – e.g. Teflon (used in your non-stick pan) to achieve the results. However this research team has successfully structured the surface of the metal and make it super-hydrophobic. This will become the intrinsic properties of the metal and cannot be rub -off or degraded.

Beside the super-hydrophobic properties, they have successfully convert a shinny metal into a perfect black material ( super absorbed) by simply structuring the surface. Turning the metal black can therefore make them very efficient at absorbing light. The combination of light-absorbing properties with making metals water repellent could lead to more efficient solar absorbers – solar absorbers that don’t rust and do not need much cleaning.

Source: www.rochester.edu/newscenter/

You don’t need special relativity to relate TIME and LIGHT

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Mechanical wristwatches consist of a multitude of minuscule components that require micrometer-range accuracies. Mechanical machining of these parts is at best difficult, and at worst simply impossible. Under these circumstances, laser technology is predestined for use in diverse manufacturing processes for all subassemblies.

  • Bezel: ultrashort pulsed laser beam is used to drill or micromachining of Bezel made of hardened ceramics, which are normally done by CNC machines.
  • Glass: ultrashort pulsed laser is used to cut the sapphire glass.
  • Hand & appliques: Fiber laser is used here.
  • Gears: Fiber laser is used here
  • Watch spring: PS laser is used to cut the spring
  • Micro-welding –  1,064nm ms pulsed laser

Machining with longer pulses always constitutes a thermal process: depending on the intensity, the material is heated, melted, vaporized or directly sublimated, which – if the parameters have been chosen correctly – can be used for cutting, welding, etc. Due to the material’s conductivity, a heat-affected zone always forms – even if this usually quite limited, on account of the laser tool’s precision, and the result of the processing is generally not adversely affected.

With ultra-short laser pulses, however, the processing of the material is fundamentally different. The brief pulse intervals result in extremely high peak pulse power and, with appropriate focus, extreme power density on the workpiece of up to 1018 watts per square centimeter. By comparison, deep-penetration welding of steel plate requires approximately 106 watts per square centimeter.

n addition to steel and precious metals, bezels – or even entire watch casings – are being made of ceramics. These have the advantage of being extremely hard, so that they are barely susceptible to dents and scratches. Drilling or the application of surface structures by ablation are once again applications for which ultrashort laser pulses are ideal.

Moreover, not only can watch crystals and watch faces made of sapphire glass be cut and drilled, they can also be marked on the interior using picosecond lasers. Rated at nine on the Mohs scale of mineral hardness, sapphires are the second hardest (surpassed only by diamonds) transparent material and thus offer enormous resistance to scratches. However, they can hardly be mechanically processed at all.

Chemically prestressed glasses are currently enjoying growing popularity; above all they are used in tablet computers and smartphones, but also for watch crystals – once again because of their hardness and scratch resistance. Here as well, the glass plates are cut precisely and cost-effectively with picosecond lasers.

Source: Trumpf Laser community

Markets and trends – laser industry

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Application trends:

  1. Laser cutting of hot forming components: especially used in German car industry. US automotive makers are picking up the pace now.
  2. Ultrashort pulse ( USP) lasers for micro-machining: mainly in the manufacturing of consumer products- smartphones and tablet. Pico- or femto- second lasers for example, are used to machining brittle and hard materials like sapphire, glass or ceramic.
  3. Laser marking market remains stable.
  4. High power diode laser for cutting/welding applications
  5. Additive manufacturing/ 3D printing : enjoys the greatest interest in automotive, aerospace industry.
  6. Semiconductor industry remains the most important markets for the laser applications, in particular for smartphones and tablets .
  7. Medical engineering: OCT, ophthalmology and dermatology.  There are huge demand for the medical products and implants.
  8.  OLED displaces: UV laser is used for the photo-thermal lift off from the substrate to the display material.

Source: EPIC / VDMA

Goodbye fake Rolex – a fight with replica watches using hidden laser image

Swiss luxury watch maker Carl F. Bucherer is currently working with a swiss company Mimotec SA and developed a very interesting way to fight against counterfeit. This new techniques is called Convert Laser Readable (CLR) -LIGA, a process used nano-surface structuring for hide a hidden message that only laser can read.

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See the cool video below :

Source: http://www.mimotec.ch/anglais/Technology/technology.html

DILAS GmbH merged with m2k-laser 2016

DILAS, the well-known diode laser company ( ROFIN subsidiaries) is merging with m2k-Laser to increase the operation efficiency. The headquarter of m2k- laser in Freiburg will be transformed into a business unit of DILAS GmbH (DILAS Semiconductor).

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Source: Dilas.com ; m2k-laser.de