By Matthew Nipper, Spectrum Plastics Group, Director of Engineering
Laser micromachining is one of the highest precision processes used in the manufacturing of medical devices. In fact, lasers are often the only option capable of producing certain delicate features, especially in thin or sensitive materials. Lasers can quickly cut micron-sized features to sub-micron tolerances without defects, thereby reducing or eliminating secondary finishing processes, shortening cycle times and accelerating time to market. Because of these advantages, lasers are quickly becoming the preferred method for micro-machining miniaturized and/or complex parts and products for medical devices, in virtually any shape or pattern.
Innovative product designs that require microscopic features are often best produced using laser machining, for example, catheters, medical balloons, and devices for neurovascular, cardiovascular, and diagnostic procedures. Features produced in polymers can be as small as 10 microns in width, with tolerances as tight as 1-2 microns.
Polymers are the material of choice for many medical devices. These materials are mechanically robust, bioinert and have excellent insulating properties. Polymers can be engineered to exhibit specific mechanical and chemical characteristics, to improve biocompatibility and performance, and can be extruded, injection molded or additively manufactured. Virtually any thermoplastic or thermoset polymer material can be laser processed with high precision, including polycarbonate, polyurethanes, ABS, FEP, polyamides, polyimides, PEEK, PTFE, PMMA, polyester , nylon, PE and acrylics.
As products become smaller and more complex, engineers must use their technical skills, materials knowledge, and experience to design processes that can create tiny, high-precision features that enhance product functionality, which can ultimately improving or saving the lives of patients.
Here are examples of commonly used high-precision laser methods:
Lasers can be programmed to remove or “vaporize” material from surfaces with sub-micron precision. Ablation selectively removes substrate or coating layers from the surface of fabricated parts, with little or no negative thermal or structural impacts on the surrounding material.
Laser cutting is ideal for manufacturing/industrial applications that require a powerful, highly precise cutting tool that creates sharp features on a microscopic scale. As products become smaller, with more functionality, complexity and tight tolerances, laser cutting is often the only method that can produce the high precision features these devices require.
Many manufactured parts today require microscopic features that can only be created with laser drilling. This highly adaptable, versatile and reliable microfabrication process is used in a wide range of industries. Laser fabrication and post-laser processing can be customized to meet unique drilling needs, optimizing applications such as micro-holes, hole arrays, blind holes and specialty portals. Micron-scale holes can be laser drilled in a variety of patterns with the utmost precision, with no burrs or residual material to clog the holes.
Wire stripping removes sections of insulation or shielding from wires and cables to provide electrical contact points for termination. Conventional stripping methods make physical contact with the conductor, which can damage the wire and slow processing speed. Laser wire stripping is much faster, offers excellent accuracy and process control, and eliminates wire contact, allowing the processing of gauges as small as 46 AWG (0.0015 inches in diameter).
Ultra-fast lasers are in high demand due to their speed, accuracy, and lack of thermal or structural damage to the material being processed. With an average pulse width of 150 femtoseconds (150 quadrillionths of 1 second), there is virtually no heat transfer beyond the dimensions of the cut, making it a “cold” process. Therefore, secondary processing is usually not required to remove burrs from cutters or improve edge quality, saving time and money.
Components and laser technology
Precision laser processing can be used for extruded medical tubing, catheters and drug delivery products, medical balloons, injection molding and flexible films. For example:
- Extruded medical tube. Lasers are high-precision machining instruments that cut micron-scale features in extruded tubing that enable specific medical applications, such as intravascular delivery of drugs or stents. Extruded medical tubing is a commonly used component in medical devices. It is made from a variety of materials and in a wide range of shapes and sizes. Important chemical and mechanical properties include heat and chemical resistance, lubricity, flexibility, kink resistance, and drug eluting capabilities.
- Catheter technologies. The lasers, which offer high speeds, incredible precision and the ability to process without thermally altering the surrounding material, are ideal for removing material by ablation or drilling a variety of micron-sized features in tubing. catheter and other materials. As medical catheters become smaller and more complex, lasers are often the only manufacturing technology capable of providing the precision needed.
- Medical balloons. Lasers play a vital role in creating detailed, high-precision medicine ball features that no other method can replicate, including; texturing, grooving and section thinning. With the latest laser technologies, tools, and materials, medicine balloons can be fabricated with microscale features, from a wide variety of materials, for neurovascular, cardiovascular, gastrointestinal, urology, and catheterization procedures. increasingly innovative.
- Injection molding. For injection molded products, lasers can be used to create micron-sized features in molds, process molded ophthalmic implants, and improve osseointegration of injection molded bioresorbable implants. Because ultra-fast lasers cause no thermal damage, they are ideal for treating sensitive implantable and bioresorbable materials.
- Flexible films. Laser processing can be used for a variety of film applications. For example, lasers can be used to create surface micro-texture patterns on thin films increasing adhesion in delicate bonding applications. Lasers are also ideal for drilling small features, such as dense arrays of holes in filters or spargers. These are often made from thermoplastic materials, which are very heat sensitive.
Spectrum laser processing
As a full-service laser solutions provider, Spectrum can manufacture high-precision parts to exact specifications in the most efficient and cost-effective manner. Spectrum excels at turning even seemingly impossible designs into high-value products that exceed customer expectations.
Not only is Spectrum a contract manufacturer of high precision laser products, but we also supply ready made laser die tubes and laser cut marking tapes online at online store.spectrumplastics.com, which can be used to speed up the development phase of your next project. For more information on Spectrum’s services and laser processing capabilities, visit www.spectrumplastics.com or call 404-564-8560.
Content sponsored by Spectrum Plastics Group