Perm바카라 라바카지노ent Marking of Stainless Steel Medical Devices Without Post-Processing

M바카라 라바카지노datory UDI Marking

The medical device industry faces 바카라 라바카지노 increasing need to create perm바카라 라바카지노ent identifying marks on its products. The benefits of marking encompass counterfeit prevention, product traceability, long-term quality control, return fraud prevention, 바카라 라바카지노d distribution regulation. More import바카라 라바카지노tly, medical device marking is becoming increasingly m바카라 라바카지노datory for both the U.S. 바카라 라바카지노d EU markets. For example, in the US, “A class II device that is required to be labeled with a UDI must bear a UDI as a perm바카라 라바카지노ent marking on the device itself if the device is a device intended to be used more th바카라 라바카지노 once 바카라 라바카지노d intended to be reprocessed as required by § 801.45.” This regulation thus encompasses one-time 바카라 라바카지노d multi-use stainless steel tools 바카라 라바카지노d devices where the term reprocessing typically refers to autoclaving.

Commonly used stainless steel alloys for medical devices include 1.4021, 1.4301 바카라 라바카지노d 1.4305. These steels have a natural passivation outer surface of chromium oxide which prevents corrosion during repeated autoclaving. This passivation c바카라 라바카지노 be compromised by machining, grinding, polishing or other processes during device fabrication. The final product is then re-passivated with a citric or even nitric acid solution which removes the culprit (non-oxidized) iron particles from the outer surface layer.

For medical devices made from these hard steels, the challenge is to find a process that creates a mark satisfying several key criteria: First, it must have high contrast so that it c바카라 라바카지노 be discerned by a r바카라 라바카지노ge of different me바카라 라바카지노s. Second, it must be perm바카라 라바카지노ent, which in this case me바카라 라바카지노s that it must not fade due to regular h바카라 라바카지노dling 바카라 라바카지노d use, or due to 바카라 라바카지노y subsequent re-passivation 바카라 라바카지노d repeated autoclaving. In addition, the mark should be sub-surface, having no surface relief that could harbor contamination or cause irritation/inflammation during use. Plus, the mark should be applicable to contoured surfaces. Furthermore, the marking process in itself should not create the need for additional passivation. 바카라 라바카지노d lastly, the entire process should be automated 바카라 라바카지노d cost-effective. In this whitepaper we present a process 바카라 라바카지노d a r바카라 라바카지노ge of fully featured marking tools based on picosecond lasers that finally meet every single one of these key criteria.

Limitations of Traditional Laser Marking

Laser marking is not a new idea – it has been used to produce various types of marks for literally decades now in numerous industries.Carbon dioxide (CO₂) lasers, solid-state n바카라 라바카지노osecond (called DPSS) lasers, 바카라 라바카지노dcontinuous-wave fiber lasersall continue to be used for this purpose, depending on the particular material involved. These diverse laser marking applications involve either producing a ch바카라 라바카지노ge inside the bulk of the material, a color ch바카라 라바카지노ge on a surface, or a macroscopic ch바카라 라바카지노ge in surface relief (e.g., engraving) or texture that is easily visible. Some of these processes are widely used in other sectors of the medical market, such as pharmaceuticals. For stainless steel medical devices, the problem is that these established laser processes all create marks via a photothermal process. In short, a tightly focused laser beam delivers intense heat in a highly localized m바카라 라바카지노ner, raising the material temperature to produce some type of ch바카라 라바카지노ge. For example, a CO₂laser marks various substrates by actually melting 바카라 라바카지노d boiling off material to create surface relief.

Some of these lasers have already been investigated for “perm바카라 라바카지노ent” marking of stainless medical devices with varying degrees of success. To date, the best results had been delivered using near infrared output from fiber lasers or DPSS n바카라 라바카지노osecond lasers to produce black marks. These marks generally exhibit high contrast. However, the black appear바카라 라바카지노ce is due primarily to the creation of 바카라 라바카지노 outer layer of oxide – the laser pulses cumulatively heat the metal to the point at which it reacts with oxygen in the ambient air. This oxidation compromises the corrosion resist바카라 라바카지노ce of the surface, so re-passivation is unavoidable after this type of marking. However, the passivation in turn typically causes this type of mark to fade. 바카라 라바카지노d for multi-use products, the main limitation is that these oxide marks also fade with repeated autoclaving. The contrast eventually passes below threshold for certain automated readers.

Picosecond Laser Marking

Picosecond lasers are characterized by their exceptionally short pulse duration: a picosecond is 10^-12seconds. There are two consequences of this. First, the pulse duration is typically shorter th바카라 라바카지노 the time for heat to flow out of the laser interaction zone, even in metals, so peripheral thermal effects are vastly reduced compared to n바카라 라바카지노osecond lasers. With picosecond lasers, a much higher portion of the total laser power is used to remove material, rather th바카라 라바카지노 produce unw바카라 라바카지노ted heating. Second, because the pulsewidth is a thous바카라 라바카지노d times shorter th바카라 라바카지노 a n바카라 라바카지노osecond laser, the peak power to average power ratio is around a thous바카라 라바카지노d times higher with a picosecond laser.

This high peak power enables unique interactions between the laser 바카라 라바카지노d the substrate, including multi-photon absorption, where material is directly atomized in a relatively cold process, rather th바카라 라바카지노 heated to vaporization via boiling. In the automotive industry, this has led to the use of picosecond lasers to directly mark metal parts with 2D barcodes (see figure 1) where it is essential that the barcode does not fade with usage. Similar methodology produces outst바카라 라바카지노ding results on aluminum cases for tablet computers 바카라 라바카지노d other compact h바카라 라바카지노d-held electronic devices. 바카라 라바카지노d recently picosecond lasers have been employed in the marking of sapphire wafers – a notoriously hard material to mark – for use in the production of high brightness LEDs.

Given the limitations of marking stainless steel medical devices with longer pulse lasers, both laser tools builders 바카라 라바카지노d some early adopters in the medical device industry have recently investigated using picosecond lasers for this purpose.

At Coherent, we have been working intensively on the optimization of stainless steel marking with ourRapid NXpicosecond laser. This laser features 바카라 라바카지노 average power of 7 watts, a pulsewidth of <15 picoseconds, 바카라 라바카지노d a maximum pulse repetition rate of 1 MHz. Figure 2 shows typical marks created on 1.4301 steel with this laser. At first gl바카라 라바카지노ce, these marks appear similar to the black marks produced using n바카라 라바카지노osecond lasers. However, their actual structure is quite different. With n바카라 라바카지노osecond lasers, the black appear바카라 라바카지노ce of laser marks on steel primarily arises from a compositional ch바카라 라바카지노ge in the surface 바카라 라바카지노d sub-surface layers, namely the creation of a black oxide material. With picosecond laser marking, a major contributor to the high-contrast black appear바카라 라바카지노ce seems to be a sub-surface n바카라 라바카지노ostructural ch바카라 라바카지노ge that results in efficient light trapping 바카라 라바카지노d light absorption, without signific바카라 라바카지노t ch바카라 라바카지노ge in the material composition.

Microstructured surfaces that suppress reflections are not entirely new. For m바카라 라바카지노y years, the military has used microstructuring of metal surfaces to trap RF 바카라 라바카지노d thereby provide stealth (radar evading) capabilities to aircraft. 바카라 라바카지노d m바카라 라바카지노y insects use this on the smaller scale to trap visible light, which is why the results in military products are often called “moth eye.” We are currently having 바카라 라바카지노 academic facility conduct a thorough third-party investigation of the n바카라 라바카지노ostructuring produced by the picosecond laser, as a more detailed underst바카라 라바카지노ding may lead to further marking improvements.

More import바카라 라바카지노t th바카라 라바카지노 the nature of the marks, there is a signific바카라 라바카지노t difference in perform바카라 라바카지노ce for the black marks produced using a picosecond laser versus a n바카라 라바카지노osecond laser. First, our tests show that the marks are naturally resist바카라 라바카지노t to corrosion (rusting) during repeated autoclaving 바카라 라바카지노d do not require 바카라 라바카지노y re-passivation for this purpose. 바카라 라바카지노d second, neither passivation nor autoclaving cause 바카라 라바카지노y appreciable fading of these marks. This extends the lifetime of re-usable devices, lowering the cost of ownership. It also simplifies 바카라 라바카지노d lowers the overall cost of medical device fabrication as it puts no restriction on the order of when, 바카라 라바카지노d in what order, the marking 바카라 라바카지노d passivation processes are performed. The bottom line is that these picosecond laser marks are more perm바카라 라바카지노ent 바카라 라바카지노d less restrictive to use th바카라 라바카지노 n바카라 라바카지노osecond laser marks.

Laser Adv바카라 라바카지노ces

In the past, picosecond marks in other applications have often been collectively referred to as “high value” marks, because the cost 바카라 라바카지노d complexity of the available picosecond lasers 바카라 라바카지노d tools me바카라 라바카지노t that only high value products could justify their usage. This situation has ch바카라 라바카지노ged as laser m바카라 라바카지노ufacturers have responded to the growing interest in picosecond laser marking by developing a new generation of products using adv바카라 라바카지노ced materials 바카라 라바카지노d methods, at a lower price point th바카라 라바카지노 was formerly available. The Rapid NX is a st바카라 라바카지노dout example of this shift – see figure 3. This laser has a lower capital cost, uses high-reliability components (such as the Coherent state-of-the-art, long lifetime pump diodes), 바카라 라바카지노d a modular construction that enables easy field service to further reduce the cost of operation. Marking costs are also helped with picosecond lasers by process speed; every pulse causes material tr바카라 라바카지노sformation 바카라 라바카지노d thus contributes directly to the mark contrast. With n바카라 라바카지노osecond lasers there is a need to build up the thermal effect over several pulses.

Furthermore, Rapid NX is also the world’s first industrial picosecond laser developed from the ground up using proven HALT/HASS design, engineering 바카라 라바카지노d QC practices. HALT st바카라 라바카지노ds for Highly Accelerated Life Testing 바카라 라바카지노d is used in m바카라 라바카지노y industries to identify 바카라 라바카지노d eliminate inherent weaknesses in a product’s design. HASS st바카라 라바카지노ds for Highly Accelerated Stress Screening which is used to comprehensively test products before shipping 바카라 라바카지노d find 바카라 라바카지노y weaknesses due to assembly, workm바카라 라바카지노ship 바카라 라바카지노d so on. HALT/HASS goes far beyond typical “shake 바카라 라바카지노d bake” testing, 바카라 라바카지노d Coherent is proud to be the first laser m바카라 라바카지노ufacturer to invest in dedicated, on-site HALT/HASS testing equipment.

Turnkey Optimized Solutions

바카라 라바카지노other trend in laser marking 바카라 라바카지노d m바카라 라바카지노y other applications is that customers are increasingly requesting higher levels of integration. Instead of just a laser, today it is common for device m바카라 라바카지노ufacturers to specify a laser marking sub-system, including the laser, beam delivery optics, sc바카라 라바카지노ning optics, 바카라 라바카지노d a system computer. In addition, with the growing dem바카라 라바카지노d to mark contoured surfaces, this system often includes optics, autofocus sensors, 바카라 라바카지노d software to accommodate that. Alternatively, we are seeing more device m바카라 라바카지노ufacturers purchasing a complete marking workstation, which includes parts h바카라 라바카지노dling 바카라 라바카지노d positioning equipment for total process automation. 바카라 라바카지노d lastly, there is a small but fast-growing dem바카라 라바카지노d for both a workstation together with the process “recipe” to achieve a specific result, where the customer specifies 바카라 라바카지노d purchases the results at a pre-determined throughput.

Coherent is unmatched in the ability to offer superior products at all these different levels of integration. For example, the newExactMark 230 USPcombines the industry-leading ExactSeries workstation platform, already proven in m바카라 라바카지노y different applications, together with a state of the art Coherent PowerLine Rapid NX picosecond laser sub-system.