How a UK Startup's Diamond Tech Aims to Cool the AI Boom

Jan de Vries · 2026-08-21

There's a quiet, energy-intensive revolution happening in the background of our digital world. Artificial intelligence isn't just smart software—it's powered by massive data centers that are getting thirstier for power by the day. A huge chunk of that electricity, it turns out, just turns into heat and vanishes. That's the multi-billion dollar problem a small UK startup, HexSeed Technology, is trying to solve with a rather brilliant, sparkly solution: diamonds. ### The Funding and the Founders HexSeed just secured over $760,000 in its early-stage funding round. That's a solid vote of confidence for a company still moving from the lab to real-world prototypes. The round was led by Carbon13, with Net Zero Technology Centre and Vento Ventures also chipping in. This investment also unlocked a provisional Partnership Grant from Innovate UK, awarded earlier this year. The brains behind the operation are a classic deep-tech trio. CEO Mark Tandy holds an Oxford MBA, CTO Dr. Leonardo Santoni has a PhD in chemistry from UCL, and COO Dr. Michael Glerum brings a PhD in Engineering from Cambridge. They're not working in a vacuum, either. They've got a tight collaboration with researchers at the University of Bristol, which is crucial for what they're trying to pull off.  ### The Heat Problem No One Talks About Let's break down the issue. Data centers are on track to consume a staggering share of the UK's grid capacity within this decade. Globally, the International Energy Agency expects AI-optimized facilities to push data center electricity consumption to 945 terawatt-hours by 2030. That's a mind-boggling number. Here's the kicker: a large proportion of that power is lost as waste heat during power conversion. It's like buying a gallon of gas and watching half of it evaporate before it even gets to your engine. The industry is moving towards more efficient components called Gallium Nitride (GaN) transistors, but they have a major flaw—they run incredibly hot. Heat is the single biggest thing stopping them from reaching their full potential. ### Why Diamonds Are the Secret Weapon So, where do the diamonds come in? Well, diamond is the best-known thermal conductor on the planet. It can pull heat away from a component faster than anything else. The problem? Traditionally, growing a diamond coating requires furnace-like temperatures that would instantly melt the delicate semiconductor device you're trying to protect. It's a classic catch-22. This is where HexSeed's innovation kicks in. Working with University of Bristol experts like Professor Paul May (diamond materials) and Professor Martin Kuball (semiconductor heat management), they're developing a low-carbon, low-temperature process. - **The Process:** It's a low-temperature microwave plasma technique that grows diamond coatings directly onto finished GaN devices. - **The Result:** The diamond acts like a super-efficient heat sink, pulling thermal energy away from the device's active regions. - **The Benefit:** The devices can run harder, last significantly longer, and, most importantly, use less energy overall. 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's Next for HexSeed? The new capital has a clear mission. HexSeed plans to demonstrate its coating process on commercial GaN power devices and start engaging with pilot customers. Their initial target market is the power conversion hardware inside data centers—the very heart of the AI infrastructure. If they can make even a small dent in that colossal energy waste, the impact could be enormous, not just for the tech industry's bottom line, but for managing our overall energy grid. It's a fascinating example of a deep-tech startup aiming to solve a foundational problem that's hiding in plain sight.