Wearable Tech Challenges: Using Biocompatible Anodizing for Health-Tracking Devices

The wearable market—comprising smartwatches, fitness bands, and even smart rings—is no longer just about steps and calories.

These are now sophisticated medical-grade instruments. However, because these devices live in constant contact with human skin, they face a unique engineering hurdle: Biocompatibility.

If the metal housing of a tracker causes a rash or leaches chemicals into the skin, the product is a failure, regardless of how accurate its sensors are. At Coboggi, we help brands bridge the gap between "industrial-strength" and "skin-safe."


1. The Nickel Problem and the Aluminum Advantage

Many traditional metal alloys (like certain stainless steels) contain nickel, a common allergen that causes contact dermatitis.

  • Why Aluminum? Aluminum is naturally hypoallergenic. It is highly resistant to the "leaching" of heavy metals.

  • The Weight Factor: In wearables, every gram matters. Aluminum offers the structural protection of metal at a weight that feels "invisible" on the wrist or finger.


2. Anodizing as a Biocompatible Barrier

Raw aluminum is rarely used in wearables; it is almost always anodized. Anodizing creates a controlled oxide layer that is integrated with the metal substrate.

  • Type II Anodizing: This is the standard for wearables. It allows for a vast array of "jewelry-grade" colors while creating a non-reactive ceramic surface.

  • The Importance of Sealing: After anodizing, the microscopic pores of the aluminum must be "sealed." Coboggi uses high-purity deionized water sealing or specialized salt sealing to ensure no dyes or chemicals can migrate out of the finish and onto the user's skin.


3. Meeting ISO 10993 Standards

For devices marketed as "health-trackers" or medical devices, the housing must often pass ISO 10993 testing. This involves:

  1. Cytotoxicity: Ensuring the material doesn't kill cells.

  2. Sensitization: Ensuring the material doesn't cause allergic reactions over time.

  3. Irritation: Ensuring the surface texture and chemistry don't irritate the skin.

At Coboggi, we work with certified material suppliers to ensure our Aluminum 6061 and 7075 alloys meet the baseline requirements for these rigorous tests.


4. Surviving the "Human Environment"

Human skin is a surprisingly harsh environment. It produces sweat, which is a mix of water, salts, and acids (low pH).

  • Corrosion Resistance: Sweat can cause "pitting" in lower-quality metals. Our hard-anodizing processes ensure that the finish remains pristine even after months of high-intensity workouts and constant moisture exposure.

  • Oleophobic Coatings: For wearables, we often suggest an additional AF (Anti-Fingerprint) coating over the anodized aluminum. This prevents skin oils from staining the metal and makes the device easier to clean.


5. Comparison: Wearable Material Options

MaterialSkin SafetyWeightDurabilityAesthetic Versatility
Plastic/PolymerHighUltra-LightLowLow (Feels Cheap)
Stainless SteelRisk (Nickel)HeavyHighHigh (Mirror Finish)
Coboggi AluminumHigh (Hypoallergenic)LightHighHighest (Vibrant Colors)

biocompatible anodized layer


Conclusion: Beauty Without Compromise

The future of healthcare is wearable. By combining the lightweight strength of aluminum with biocompatible anodizing, Coboggi enables brands to build devices that are as safe for the body as they are powerful for the user.