HexSeed Technology Raises £600K for Diamond-Cooled GaN Chips

HexSeed Technology is attacking AI infrastructure from an unusually physical angle: the heat trapped inside the electronics moving power around a data centre. The Scottish startup is developing diamond coatings for gallium nitride, or GaN, power devices, using one of nature’s best thermal conductors to pull heat away from chip hotspots before it limits performance, reliability or energy efficiency. Its longer-term ambition goes further by using captured CO₂ as the carbon feedstock for those high-value materials.

The company has raised more than £600,000 in early funding led by Carbon13, with participation from Net Zero Technology Centre and Vento Ventures. The cumulative investment also unlocks an Innovate UK Partnership Grant that was provisionally awarded earlier this year. HexSeed will use the capital to demonstrate its coating process on commercial GaN power devices and move toward pilot customer engagements, initially targeting data-centre power conversion.

HexSeed was founded in late 2025 by Mark Tandy, Dr Leonardo Santoni and Dr Michael Glerum. Tandy brings an Oxford MBA, Santoni holds a chemistry PhD from UCL, and Glerum has a Cambridge engineering doctorate. The team is also working with University of Bristol researchers as it develops the underlying process.

The technical challenge is temperature. GaN devices can convert power more efficiently than conventional silicon components, but higher power density concentrates heat in small areas. Diamond conducts heat extremely well, yet conventional diamond-growth temperatures can damage a finished semiconductor. HexSeed is developing a lower-temperature microwave-plasma process that deposits diamond films directly onto completed GaN devices, allowing heat to escape closer to where it is generated.

That gives HexSeed two problems to solve at once: make increasingly power-hungry AI infrastructure more thermally efficient while creating a valuable destination for captured carbon.

The next step is proving the process beyond laboratory conditions. If HexSeed can translate its coatings onto commercial devices at manufacturable scale, diamond could become less of a specialist material and more of a thermal layer helping AI infrastructure push higher power without paying the same penalty in heat.