Cambridge Heavy Industries builds desktop fusion device
Original: Cambridge Heavy Industries has been quietly building a desktop fusion device
Why This Matters
Compact, high-iteration fusion hardware could dramatically cut the time and cost to commercialization.
Cambridge Heavy Industries, a stealth MIT-area startup, has raised $6.2M seed funding to develop a benchtop laser fusion device capable of running 50–80 experiments daily, aiming for a power plant within a decade.
Most fusion projects lean on enormous magnets or laser halls the size of stadiums. Cambridge Heavy Industries is doing the opposite. The Cambridge, Massachusetts startup has been operating quietly near MIT, building a laser-driven fusion reactor small enough to sit on a tabletop.
Co-founder and CEO Yun Kai told TechCrunch exclusively that the compact form factor is a deliberate engineering choice. "We purposely built a small modular reactor. It's tiny, it's benchtop. Because it's small, it makes everything easier," he said. The device can run 50 to 80 fusion shots per day, with results feeding AI-optimized simulations to accelerate design improvements.
The reactor uses inertial confinement fusion—the same principle behind the landmark 2022 NIF experiment that achieved net energy gain—but strips down the laser count significantly. Two main lasers drive ignition: one is split into multiple beams delivering light in concentric rings that hit a flat, round fuel target in timed succession, building an inward compression wave. A second laser then fires to generate heat and a magnetic field at the center, triggering fusion at relatively low laser power.
The concept originated in MIT chemist Keith Nelson's lab, where researchers studying materials under extreme pressure realized they were approaching fusion-relevant conditions.
The company just closed a $6.2 million seed round led by Azolla Ventures, with Overlay, Neta Foundation, P3A, MassCEC, and the Rothrock family participating. The 10-year roadmap targets a pilot power plant roughly two basketball courts in size—large by benchtop standards, but far smaller than conventional fusion facilities.