Burning Issues: The Thermal Challenges of “Wearables”

8 August, 2019

Wearable technology is on the rise. From fitness trackers and smartwatches, to implantables and head mounted displays, “wearables” seem set to keep rising in popularity. In fact, industry analysts predict that by 2020, global shipments of wearable devices will grow to 190 million units. As this market grows and devices evolve, brands need to work harder to ensure that their devices are meeting consumer expectations for weight, comfort and reliability. 

Testing Times

Earlier this year, Nike launched a product described as its “most tested” in history, the AdaptBB. This “smart shoe,” based on the self-lacing trainers from Back to the Future, has undergone thousands of hours of resistance testing — against impact, water and heat.

Clearly, introducing electronics into wearable products has major implications for the testing phase, with thermal management proving a vital factor to consider. And with products such as the Intel-backed smartwatch Basis Peak having to issue a complete recall due to an unexpected thermal complication, you can see why.

An active LED on the back of the watch was at risk of overheating and burning wearers. Only 0.2% of the LEDs suffered thermal complications, but the flaw was so baked-in to the design there was no choice but to go back to the drawing board for a complete redesign.

Avoid Design Disaster

To avoid such baked-in complications, it’s essential that engineers factor in thermal management from the very start of the design stage. 

This is especially true for wearables, as due to their small sizes and proximity to the skin, overheating is a more serious, and potentially dangerous, problem. 

With limited heat/thermal dissipation paths available, adding fans or other elements that increase the size or weight of the device are impractical. As such, alternatives for heat dissipation and internal heat flow need to be carefully considered.

Thermal Simulation Solution

But how can engineers get these vital insights? 

Using thermal simulation software, such as 6SigmaET, manufacturers can test their product early in the design process — calibrating the position of components for improved heat flow and making sure it meets all regulatory requirements.

Our research has shown that 75% of design engineers don’t test the thermal reliability of their designs as early as they could, while 56% wait until after a prototype has been produced. A further 27% actually wait until after the product is completed!

This is an incredibly risky strategy that could lead to less reliable products, less comfortable devices and the potential for expensive recalls on the part of manufacturers. 

Using CFD software for thermal simulation in the early planning stages can provide the necessary visibility on the overall heat and temperature distribution both inside and outside the device. This in turn can help engineers to develop cost-effective solutions from the onset, improving reliability for customers while also improving their ROI. 

When it comes to new applications for thermal management, wearable technology is just the tip of the iceberg. From artificial intelligence to 5G phones, new hardware, material and technology trends are driving a whole host of previously unseen thermal considerations that engineers will need to simulate and test before their products are ready for market. To find out more about these trends, download 6SigmaET’s latest Thermal Focus whitepaper.

Blog written by: Tom Gregory, Product Manager