Acree Technologies Inc.

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Coatings for Medical / Biomedical Devices and Surgical Instruments

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Biomedical devices are designed to improve quality of life, and current methods are remarkable in their scope and efficacy. In fact, they are so commonplace as to almost be considered "routine." However, surgery to implant a biomedical device is still not a thing to be taken lightly. The implanted devices have to perform perfectly and to last. Therefore, they need to be:

  • Biocompatible - chemically inert (non-mutagenic, non-hemolytic, non-pyrogenic) to prevent rejection and/or adverse reactions
  • Low Friction - moving surfaces must have low friction characteristics to ensure precise, smooth operation
  • Durable - All surfaces of an implant must be durable and corrosion resistant to ensure long and trouble-free operation. When wear does occur, the resulting byproducts must not be capable of embedding in nearby tissue 

PVD coatings have proven critical in meeting these requirements for all materials commonly used in biomedical devices-stainless steel, titanium, ceramics, and other advanced materials. Acree has created high performance biomedical coatings. Acree's biomedical coatings feature:

  • Nanocrystalline structure that is free of pores, columnar structures, and inclusions (any of which can lead to cracks, corrosion, or wear). Nanocrystalline structure has a lower coefficient of friction than commonly used polymers and polycarbonate materials
  • Very high levels of process control, coating uniformity, and adhesion

Acree also has developed great expertise in depositing these thin films on the devices, which is an art in itself. Acree has proven successful with the following biomedical applications:

  • Corrosion resistant and biocompatible coatings for pacemaker electrodes
  • Wear resistant, biocompatible coatings for Left Ventricular Assist Devices (LVAD)
  • Diamond like Carbon (DLC) coatings for implantable joint replacements 
  • Catheters - Acree has developed a number of coatings for catheters, including, hermetic coatings to prevent water and fluid infiltration, lubricious coatings that allow easy insertion into sheathes and tissue, and the fabrication of advanced electrodes for state-of-the-art catheters that allow real time feedback and control during use. For the advanced electrodes, Acree has developed proprietary patterning techniques that allow small (< 1mm in size), complex shaped, multilayered electrodes to be applied to the catheter. These electrodes are used for a variety of feedback and diagnostic treatments.
  • In conjunction with a major biomedical manufacturer, Acree currently is performing research and development on ultra-high endurance coatings for the next-generation of replacement joints.

In addition to high performance, biomedical coatings require a thorough quality control process. Acree has been certified as an industry supplier under FDA regulations (21 CFR Part 820). These regulations cover the full range of manufacturing: quality management and organization, device design, buildings, equipment, purchase and handling of components, production and process controls, packaging and labeling control, device evaluation, distribution, installation, complaint handling, servicing and records. Earning this certification is exceedingly difficult and time consuming, and relatively few firms in the coating industry have done so.

Coatings for Surgical Instruments

In surgery, a doctor needs the right surgical instrument, and that instrument needs to perform perfectly. The type of coating on an instrument is a key element in its performance. PVD coated tools deliver superior performance because the coatings modify the surface properties of a device without changing the underlying material properties. Depending on the application, PVD coated surgical instruments exhibit the following properties:

Biocompatibility - Coatings are non-mutagenic, non-hemolytic, non-pyrogenic, and are Grade 0 (non-toxic) in MEM Elution Cytotoxicity testing
Chemical Barrier Layer – Coatings create a chemically inert barrier. For example, they provide protection against Nickel (Ni) sensitivity. Also, certain coatings create a dielectric layer
Improved Lubricity/Reduced Friction – Coated instruments feature improved lubricity. They have significantly lower Coefficients of Friction (e.g. 0.35 vs. 0.7 for coated vs. uncoated steel) than un-coated ones. Coated instruments therefore require less force due to operate
Improved Wear Resistance – Coated instruments retain a sharper cutting edge for longer, and the coating also prevents material erosion
Improved Corrosion Resistance – Surgical instruments must be sterilized, and the autoclave process (both steam and chemical) can induce corrosion. PVD coatings are compatible with the sterilization process, and they improve the corrosion resistance of stainless steel. Titanium Nitride (TiN) and Chromium Nitride (CrN) are both effective coatings for this purpose.
Appearance/Aesthetics-Coated instruments are easier to identify in surgery. For manufacturers, coatings can create a unique look for brand identification in the marketplace
Acree has developed specific PVD coatings and processes to impart the characteristics described above to surgical instruments. All of our coatings demonstrate excellent micro-hardness, lubricity and adhesion characteristics.


Telephone: 925-798-5770