How a UK Startup is Using Diamonds to Cool the AI Boom

Jan de Vries · 2026-08-21

You know how your laptop gets hot when you're running too many programs? Imagine that, but on the scale of an entire city's power grid. That's the challenge data centers face, especially as the AI revolution kicks into high gear. They're massive energy hogs, and a huge chunk of that electricity just turns into waste heat. A UK startup called HexSeed Technology thinks it has a surprisingly elegant solution. And it just raised over $750,000 to prove it. Their secret weapon? Diamonds. ### The Heat Problem No One Is Talking About Let's talk numbers for a second. The International Energy Agency projects data center electricity use could hit a staggering 945 terawatt-hours by 2030. That's a mind-boggling amount of power. A significant portion—some experts say up to 40%—isn't even used for computing. It's lost as heat during power conversion. As AI models get more complex, this problem only gets worse. We're building smarter machines, but we're wasting the energy that powers them. HexSeed is tackling this at the transistor level. Most modern electronics are switching from silicon to a material called Gallium Nitride, or GaN. It's far more efficient. But here's the catch: it runs incredibly hot. That heat limits its performance and lifespan. It's like having a supercar engine that overheats before you can hit top speed. ### Why Diamonds Are More Than Just Pretty This is where HexSeed's diamond coating comes in. Diamond is the ultimate thermal conductor—it pulls heat away faster than anything else. The problem? Traditionally, growing a diamond coating requires temperatures so high they'd melt the very semiconductor device you're trying to protect. It's a classic catch-22. HexSeed, working closely with researchers at the University of Bristol, cracked the code. They've developed a low-temperature microwave plasma process. Think of it like a gentle, precise spray that grows a diamond film directly onto a finished GaN chip. No destruction, just protection. As CEO Mark Tandy put it, "This funding will allow us to take our low-temperature diamond coating technology from laboratory demonstration to working GaN devices." ### What This Means for the Future This isn't just lab curiosity. The potential impact is massive: - **Cooler, Faster AI:** More efficient cooling means AI chips can run at higher performance for longer. - **Energy Savings:** Less wasted heat translates directly to lower electricity bills and a smaller carbon footprint for the tech industry. - **A New Market:** HexSeed is turning captured CO2 into high-value supermaterials, creating a circular economy angle. The recent funding round, led by Carbon13 with participation from Net Zero Technology Centre and Vento Ventures, also unlocked a Partnership Grant from Innovate UK. HexSeed plans to use the capital to demo their coating on commercial devices and start talking to pilot customers. Their first target? Data center power conversion hardware. The founding team is a powerhouse trio: Mark Tandy (CEO, Oxford MBA), Dr. Leonardo Santoni (CTO, PhD in chemistry from UCL), and Dr. Michael Glerum (COO, PhD in Engineering from Cambridge). They founded the company in late 2025, and they're moving fast. It's a fascinating intersection of deep tech, sustainability, and sheer necessity. As our digital world gets hungrier for power, innovations like this aren't just nice-to-have. They're essential. HexSeed's approach shows that sometimes, the most valuable tech isn't about making things faster, but about making them run cooler and smarter. And in this case, a little bit of diamond might just be the spark that changes the game.