The use of lasers to mark surgical instruments has become of greater significance, however, the parameters used in these applications are not always fully appreciated. The medical industry, in particular, has utilized laser technology primarily to mark, weld, and cut medical devices for years. Lasers address the need for microscopic applications: to cut widths measurable in microns, spot welds with heat affected zones barely visible to the unaided eye, and highly resolved biocompatible markings that enable traceability of instruments and implants. In common with other industries, medical devices and pharmaceutical businesses turn to lasers for a one-step, fast, flexible, permanent, and a highly automated marking process.

Fig. 1 – Shown is a 20w pulsed fiber laser with bench top laser safety enclosure.

Laser technology as a precise and extremely selective material processing method is steadily gaining importance in the medical industry. A contributing reason for this is that laser technology allows for a part to be marked with no damage to the chemical passivation that is required for corrosion resistance and to prevent germs from embedding within the material. The resulting marked surface maintains its anti-corrosive coating even after years of usage, cleanings, and sterilizations.

There has been a massive push both within the federal government and private sector alike to improve the identification and trace-ability of components. Products falling within the parameters of requiring such a mark may need barcodes to permanently ID products for subsequent automated tracking processes. Industry- and vendor-dependent, the codes must have the capacity to contain large data such as serial and part numbers as well as place and date of manufacture. Often, and especially with regards to medical devices, marking space is not limitless. This benefits a laser marker as it can produce a highly resolved ID/2D matric code of greater than 20 characters into a space of a few millimeters.

Currently there are few alternatives to laser marking parts within the medical field. Methods such as ink jet, hot foil, and screen printing cannot be tolerated in marking implants or invasive surgical tools due to the addition of other chemical compounds. This also holds true for packaging or dispensing product marking as many of these items are filled inside of clean environments.

In 2007, Congress passed legislation directing the FDA to develop regulations establishing a unique device identification (UDI) system for medical devices. The purpose of the initiative is to improve the quality of information in medical device adverse event reports, which will help the FDA identify product problems more quickly, better target recalls, and improve patient safety. In addition, the legislation section 519(f) was amended stating that: “The UDI would also be required to be directly marked on the device itself for certain categories of devices for which the labeling requirement may not be sufficient, for example, those that remain in use for an extended period of time and devices that are likely to become separated from their labeling.” See!documentDetail;D=FDA-2011-N-0090-0001 .

As a result, laser marking has become one of the preferred identification processes. The high-quality and high precision marks coupled with system reliability and repetitive accuracy make it an ideal solution when manufacturing under current FDA requirements. Manufacturers utilizing equipment capable of repetitive accuracy have a distinct advantage. System providers offering either vision systems standard or as an available turnkey option afford the laser operator the capability of detecting varied component positions and defective or flawed parts. Once identified, the parts in question can either be marked “Defective” or have the mark adjusted to align appropriately.

As recent as the last several years major developments and innovations in laser marking medical plastics have occurred. Lasers operating within 532 nm to 355 nm have seen a dramatic increase in effectiveness and have been found to accommodate the requirements for invasive applications. Laser markers operating within the 355nm UV spectrum produce only minimal heat and therefore photo-chemically colorize the material surface rather than foaming it. The resulting flat marked surfaces impedes germs’ ability to fix themselves to the material, ultimately reducing the risks of them penetrating the body. (See Figure 1)

Today, 532nm to 355nm laser markers apply high precision, damage-free, and lasting marks on the most sensitive products and parts that need to be sterilized (i.e., catheters or invasive devices such as insulin pumps). Materials once believed to be not markable, such as silicones or polyamides, can now be marked with extra fine and high contrast detail, and no longer require solvents or material additives to aid in the marking process.

Laser marking has become essential to the manufacturing of components for the medical industry. Laser system’s versatility, accuracy, benefits, and cost savings have benefited manufacturers by keeping them compliant with FDA regulations while minimizing the expense of complete product redesigns. Laser system manufacturers are invariably seeking ways and adapting machines to achieve greater automation, ideally through less parts handling and greater operational efficiency. Whether adaption is achieved through a color vision system, barcode reader, improved axis control, or software or laser improvements, it can be guaranteed systems will continue to improve year after year.

This article was written by Nathanael Hannah, Operations at LNA Laser Technology, Pawtucket, RI. For more information, Click Here .