AI startup HexSeed raises £600k backed by Carbon13 and Net Zero Technology Centre
This article covers HexSeed, an Aberdeenshire AI startup, which has raised £600k in a pre-seed funding round to scale a low-temperature process that deposits ultra-thin diamond films onto finished gallium nitride power chips. The development aims to improve thermal management for GaN power devices used in AI data centres, supporting wider GaN adoption and addressing heat-related limits on performance and energy efficiency.
HexSeed, an Aberdeenshire AI startup, has raised £600,000 in a pre-seed funding round to scale a low-temperature process that deposits ultra-thin diamond films onto finished gallium nitride (GaN) power chips — a move aimed at easing the thermal limits that constrain GaN adoption inside AI data centres.
Why it matters
GaN transistors are increasingly favoured over silicon for high-density power conversion because they are more efficient. Their wider use in hyperscale data centres, driven by AI workloads, however, brings a new problem: heat. Diamond is a superior thermal conductor, but conventional diamond growth requires temperatures that would damage finished semiconductors. HexSeed’s process aims to apply diamond coatings after device fabrication at temperatures low enough to preserve the chips, potentially allowing GaN devices to run harder, last longer, and consume less energy.
The timing matters: the International Energy Agency projects global data centre electricity consumption could more than double to roughly 945 TWh by 2030, with AI-optimised facilities a major driver. Improving thermal management in power conversion hardware addresses a tangible energy and performance bottleneck for the sector.
Inside the product
HexSeed is developing a microwave plasma technique to grow diamond films directly on completed GaN devices. The company says the coating improves heat extraction from active regions of the chip, removing the trade-off between thermal performance and device survivability that has limited post-fabrication treatments.
Development work is happening with researchers at the University of Bristol, including Professor Paul May (diamond materials) and Professor Martin Kuball (semiconductor devices and thermal management). The next technical milestones are demonstration of the coating on commercial GaN power devices and progression toward pilot engagements with data centre power conversion hardware suppliers.
Who are the investors?
The round was led by Carbon13, a Cambridge-based climate-tech venture builder. Participants include Aberdeen’s Net Zero Technology Centre and Italian venture firm Vento Ventures. The funding also unlocks a provisional Partnership Grant from Innovate UK, which supports collaborative technology development and could accelerate HexSeed’s move from lab demonstrations to device-level pilots.
Carbon13 positions the opportunity as addressing a sizeable data centre market under pressure from AI demand. Net Zero Technology Centre brings regional industrial and energy transition links, while Vento Ventures provides continental European investor reach.
If you're researching potential backers in this space:
- Explore our list of AI venture capital firms in the UK
- Browse our directory of AI angel investors in the UK
Founder perspective
In the announcement, Mark Tandy, chief executive at HexSeed, said:
Data centres are on track to consume a significant share of UK grid capacity within the decade, and a large proportion of that energy is lost as heat in power conversion. This funding will allow us to take our low-temperature diamond coating technology which we are developing from laboratory demonstration to working GaN devices.
HexSeed was founded in late 2025 by Tandy (CEO, Oxford MBA), Dr Leonardo Santoni (CTO, PhD in chemistry from UCL) and Dr Michael Glerum (COO, PhD in engineering from Cambridge). The team combines materials science and device engineering experience with commercial and operational leadership.
The bigger picture
HexSeed sits at the intersection of several trends: the migration of data centre power electronics from silicon to GaN; the surge in AI-driven demand for compute capacity; and a policy and investor focus on technologies that improve energy efficiency. If HexSeed’s diamond-on-GaN process proves robust outside the lab, its addressable market is global and measured in terawatt-hours rather than regional units.
For the UK and European ecosystem, the deal highlights continued interest from AI investors and energy-transition backers in hardware-level solutions to the data centre energy challenge. Support from Innovate UK and regional centres reflects how public and private funding are increasingly aligned around decarbonising AI infrastructure and commercialising deep-tech hardware innovations.
They've invested in HexSeed
Get to know these AI investors
| Investors | Investment Focus | Startup Investments | Round Size | Connect |
|---|---|---|---|---|
 Vento Ventures( ) Turin, Italy  | ||||
| All investors | All investor sectors | All funded startups | All funding rounds |
Click here for a full list of 7,589+ startup investors in the UK