HexSeed Technology closed an over £600,000 seed round, publicly announced August 18, 2026, led by climate-tech venture builder Carbon13, with backing from Net Zero Technology Centre and Vento Ventures. The Banchory, Scotland–based company is attempting something that sounds almost alchemical: growing diamond films on finished semiconductor chips using captured carbon, then deploying those coatings to manage the escalating heat crisis in AI-driven data centers.
The round also triggered a partnership grant from Innovate UK, though the company declined to specify the amount. For a startup barely a year old, the capital represents validation of a technical gamble that sits at the intersection of materials science, thermal engineering, and the infrastructure strains now visible across the hyperscale computing industry.
From Lab Bench to Live Chips
CEO Mark Tandy says the money will push HexSeed's low-temperature diamond coating process beyond laboratory demonstrations and onto working gallium nitride devices. "This funding will allow us to take our low-temperature diamond coating technology which we are developing from laboratory demonstration to working GaN devices," Tandy explained in the announcement. The target market is pilot engagements with data-center power conversion hardware providers, a sector where thermal inefficiency translates directly into wasted electricity and shortened component lifespans.
The core technical challenge is straightforward, if not simple. Diamond conducts heat better than any other bulk material, but traditional diamond deposition methods run so hot they would destroy the delicate semiconductor structures underneath. HexSeed is aiming to validate a low-temperature microwave plasma process that operates below the damage threshold of finished chips, bonding diamond films directly to gallium nitride power semiconductors after fabrication. If it works at scale, the coatings could reduce junction temperatures, extend device lifetimes, and squeeze more efficiency out of power conversion equipment—claims the company is now racing to prove in commercial settings.
The science draws on years of academic work. HexSeed collaborates with University of Bristol researchers Prof. Paul May, whose specialty is diamond materials, and Prof. Martin Kuball, who studies semiconductor device thermals. The company frames itself as a carbon-capture-utilization venture developing carbon-derived advanced materials, with industrial diamond coatings as the opening product line. Whether that broader vision materializes or remains aspirational will depend on how well the first product performs.
Heat, Power, and the AI Bottleneck
The timing is no accident. Data center electricity demand is expected to more than double by 2030, reaching roughly 945 terawatt-hours, according to International Energy Agency projections. A meaningful share of that consumption gets lost to power conversion inefficiencies and heat management. As AI workloads push chip densities higher, the thermal problem compounds. Wide-bandgap semiconductors like gallium nitride promise better performance than legacy silicon, but they also generate concentrated heat that conventional cooling struggles to handle.
HexSeed's bet is that diamond coatings on next-generation power chips can reclaim some of that waste. The company completed Carbon13's Cohort 9 program a few months before the August funding close, according to a Carbon13 post. Net Zero Technology Centre, which operates the Aberdeen-based TechX accelerator, named HexSeed to its 2026 cohort in March; that program distributed £400,000 across eight startups. Vento Ventures rounded out the investor group.
Team and Path Forward
Tandy, who holds an MBA from Oxford, co-founded HexSeed with Dr. Leonardo Santoni (CTO, PhD in chemistry from University College London) and Dr. Michael William James Glerum (COO, PhD in engineering from Cambridge). The company lists between two and ten employees on LinkedIn and is based in a town better known for whisky distilleries than semiconductor innovation. Partnerships include industrial diamond supplier Shannon Abrasives and an Innovate UK Knowledge Transfer Partnership that supports the university collaboration.
Next steps are validation and customer conversations. HexSeed plans to prove its coating process on commercial GaN devices, then approach data center operators and power electronics manufacturers. The company would not disclose its valuation, a common stance for early-stage ventures wary of locking in a number before product-market fit becomes clear.
Whether diamond-coated chips become standard infrastructure or remain a niche solution will hinge on cost, manufacturability, and whether the thermal gains justify the added complexity. For now, HexSeed has bought itself time to find out.
