Building FitBit + AI Data Centre Cooling Systems

In the latest episode of the Dinis Guarda Podcast, Larry Yang, Chief Product Officer at Phononic, discusses innovations in solid-state cooling technology for data centres, AI processors, and environmental impact, Fitbit and the evolution of chip architecture. The podcast is powered by Businessabc.net, Citiesabc.com, Wisdomia.ai, and Sportsabc.org.

Larry Yang is a technology leader with an engineering background. He is currently the Chief Product Officer at Phononic, a company that offers solid state cooling innovations, delivering high-performance energy-efficient solutions for data centres, opto, cold chain, eGrocery, pharma, and HVAC. As the Director of Product Management for Fitbit Devices at Google, Larry led Fitbit’s core wearables portfolio, which generated over $1 billion in annual revenue with over 25 million active users.

During the interview with Dinis Guarda, Larry Yang discusses Phononic's contributions to various industries through their solid-state cooling technology:

"We built the world's first solid state powered grocery freezer. It’s a tote-size form factor. We deliver a tote that allows the operator to bring it out to the store floor, put your milk in a refrigerator tote, put your ice cream in a freezer tote, bring it back to the staging room, and leave it there.

We've deployed this product at Sam’s Club and ShopRight, and they're seeing space savings, labour savings, and energy savings. We’ve delivered our tote solution to a grocery store in the Midwest called Meyer, which is running central fill pharmacy operations.

Our solution saves energy and space while maintaining temperature control. Solid-state technology allows us to turn on and off quickly, delivering cooling exactly where and when it’s needed. We operate an IoT cloud to analyse energy efficiency, utilisation, and error states, ensuring optimal performance."

The success of Fitbit

Larry discusses the success behind Fitbit's design, emphasising user-friendly, minimal UI and its impact on million:

"There was already a trend towards appreciating data, collecting data, and measuring what you do.

The very first Fitbit had no UI. There might have been an LED that told you if the battery was dying or not, but that was about it. Everything was on the smartphone, right?

And so, by having that simple UI, there were no buttons to push. You just clipped it on. The next one had, I think, four LEDs on it, but that was it.

It was a simple band that you put on, and all those LEDs told you how your progress towards your goal was. If your goal was 10,000 steps, then one LED would light up if you're 25% of the way there, three would light up if you're 75%. And that was it.

One of my product design mantras is that the best UI is no UI. There are no buttons to push, then the consumer doesn't worry about whether or not to push the button.

The smartphone, you know, was also, I guess, the other trend taking off. And so this was a much better user interface surface for looking at your data, interacting with it, etc."

Phononic: Sustainable Solid-State Cooling

Larry explains the core innovation behind Phononic, focusing on its solid-state cooling technology:

"Phononic builds solid-state cooling devices. We use a material called a thermoelectric material. That's a material that has a property where if you apply an electric current, one side gets hot and the other side gets cold.

If you reverse that current, the other side gets hot, the other side gets cold. Think of it as a miniature heat pump with no moving parts.

So we build these chips. We also build the subsystems that go around it. We also have software control. We have an IoT cloud that we can send data to where we can analyse energy efficiency, utilisation, error states, and all of that.

These we would put on top of lasers at the ends of fibre optic cables that keep the lasers cool.

We also make larger ones. This one can go into a refrigerator. These are actually double-stacked ones we can make freezers out of.

We'll actually build modules of them and in some cases encapsulate them so it's easy to assemble and test."

On the environmental impact of Phononic's technology, Larry says:

"What brought me to Phononic actually was the fact that this solid state technology can replace the conventional form of refrigeration and cooling which is using hydrofluorocarbon vapour compressors.

Hydrofluorocarbons are 2,000 times more harmful to the environment than CO2.

As we understand, the climate is changing and anything we can do, especially with the demands of cooling ever increasing, for all of the demands and use cases we've been talking about, now more than ever, we need alternatives.

It's not just better at eliminating those refrigerants. As you can see from what I just showed you, the form factor is extremely small."

We can use it in places where you can't fit a vapor compressor in. It is solid state, so it's much more responsive. We can bring cooling on demand when you need it, where you need it. That results in energy savings as well. And talk a little about that in some of the applications."

AI and data centers

Larry discusses Phononic's innovative cooling solutions for high-performance computing and networking, focusing on data centres and the challenges faced in cooling advanced AI processors:

"At the heart of AI or cloud computing, or even blockchain mining is a computer. You also have to connect many processors together, and so the network is also very important to bring them together.

Most of the data that's being sent around the world, even between or inside data centers, are sent on fiber optic cables. Fiber optic cables are strands of glass with lasers that sit on the ends. The lasers are sending the data.

When a laser is sending data faster and faster, it gets hot, it gets out of spec, and it gets literally out of tune because it's no longer sending at the right frequency. These little chips I was showing you earlier, they sit on the ends of fiber optic cables. Our chip keeps the laser cool and keeps the laser playing in tune.

We’ve been doing this for about eight years now and have shipped over 30 million devices that cool these lasers. That number is growing because as data rates get higher and higher, the demand for lasers to go faster and faster is ever increasing. Our solution is in all the major hyperscalers. We're in Google, Amazon, Microsoft, Meta, etc.

As data rates get higher and higher, the demand for lasers to go faster and faster is ever increasing. Phononic’s cooling technology ensures these lasers stay cool and operate at optimal performance, which is crucial for high-speed data transmission."

Larry explains the crucial role of cooling systems in AI data centers:

“One of the things that sets an AI processor apart from a general-purpose processor is the fact that it's using a GPU, a graphics processing unit. Graphics processor units are traditionally used in gaming applications, but what's unique about its architecture is it is massively parallel.

The power demands and thermal demands just really skyrocket. Today's AI processor chip module uses about a thousand watts of electricity, which means there's a thousand watts of heat coming out.

In a typical AI data center rack, you'll have like a hundred of these processors, and so now you're talking about 100 kilowatts of electricity going in and 100 kW of heat getting out. That amount of heat is like 16 dual double burner Weber barbecue grills all packed inside the space of a phone booth. So it's a ton of heat.

When OpenAI talks about their 5 gigawatt Stargate data center, 5 gigawatt is enough heat to keep a city twice the size of Detroit warm throughout an entire Michigan winter. This is phenomenal amounts of heat, not just in density itself but also the total amount of heat being created.

Phononic’s cooling solutions are integral to managing these extreme heat demands in AI data centers, ensuring processors remain cool and operational. Our solid-state technology is the key to keeping these high-performance processors at optimal temperatures, preventing them from overheating and ensuring continued efficiency."