The medical industry has an obvious need for the absolute highest standard in precision metal parts to ensure that surgical instruments, for instance, function smoothly without fault. The metal parts used in medical applications also require a combination of corrosion resistance, mechanical strength properties, and material biocompatibility. They often must be intricately designed small tools. Chemical etching is a method of metal manufacturing that can ensure such high quality and reliability.
In this article we’ll look at some of the key benefits of the chemical-etching process and how it applies to the medical industry. Most of the benefits come from the very nature of the chemical etching process, which is able to shape and etch metal into fine, precise, and intricate designs without affecting any of the metal’s inherent properties. This is where the manufacturing technique of using chemical etching really shines and offers a multitude of benefits within the medical industry.
Micro Parts for Medical Devices
Thanks to chemical etching, we’re able to produce complex, ultraprecise, and stress- and burr-free miniature components of bio-compatible materials in a matter of days. Chemical etching also allows us to achieve thicknesses of 25 μm, for example. Depending on the metal, 10% of a material’s thickness can be etched chemically with a minimum tolerance of 12 μm, and there may be other possibilities depending on the requirements.
A great range of practical applications can be found from precision filtration and calibration products through to microfluidics and medical implantables. Here’s a sample of just a few of the products we’re able to manufacture thanks to chemical etching:
- Microfluidic channels
- Hearing-aid components
- Precision mesh
- Precision sieves
- Masks: optical, evaporation, and sputtering
- Surgical blades
Mass Production of Medical Devices
Thanks to the process of using etchants that erode away the metal, we're able to go from prototyping to large-scale production runs within just a few days. This is because we don’t need to machine the stencils or work on only one part of the sheet metal—chemical etching works on the whole piece concurrently. As the stencil/pattern design is all done on the computer, it’s an easy fix to adjust the prototype until the final product is agreed upon. Again, because of the very nature of the chemical etching manufacturing method, we’re able to achieve highest-standard quality that is also repeatable on a large scale, which is important in the medical industry.
Stainless steel is one of the most common alloys used across virtually every industry and will no doubt be found even in your cutlery drawer. There is good reason that it’s so widely used. Chromium provides corrosion and scratch resistance, nickel offers a smooth and polished finish, and molybdenum improves hardness and helps to sustain a sharp cutting edge when used in medical instruments. At Tecan, stainless steel is one of our most commonly used metals, precisely because of these great benefits.
Another common alloy employed within the medical industry is cobalt-chromium based alloys, which are often found in dental and orthopedic implants. These materials are resistant to corrosion and wear, have excellent biocompatibility, and have properties that replicate those of the body structures they’re replacing.
Both alloys (along with others such as titanium) offer the perfect properties for use within the medical industry and as a result make for excellent choices for medical instruments.
Benefits of Chemically Etched Parts
As mentioned earlier, chemical etching results in a finished product that is both burr and stress free and as such requires little to no post-processing. Because the etchant erodes only the unwanted material, the metal suffers no embrittlement nor heat-induced distortion as a result of a high-energy process such as laser or machine-stamping, which can alter the metals’ structure. During the etching process, the metals maintain all their original desired properties, and we are left with the final result after the manufacturing process is complete.
Intricate Designs from Chemical Etching
A great number of medical products require extremely precise and intricately designed metal parts. One of the great advantages of employing chemical etching in the manufacturing process is that design complexity is not a limiting factor. Stencils can be made on computer software and then transmitted to the photoresist for shaping by the CAD-designed stencil to create the desired shape. This translates to a quick and seamless manufacturing method that is also more affordable because less is involved in the production process than in other etching/cutting methods. It’s easily iterated digital tooling is completely controllable, scalable, and customizable to suit whatever the requirements may be. This ensures a production process that is low-risk, economical, and with lead-times measured in days not weeks.