The Cambridge, Massachusetts-based startup Cambridge Heavy Industries is developing an experimental nuclear fusion device that can fit on a desktop, in an attempt to reduce the size of fusion systems typically associated with massive industrial facilities and large arrays of lasers or magnets.
The company is operating in stealth mode from a small laboratory near the Massachusetts Institute of Technology (MIT), and co-founder and CEO Yoon Kai demonstrated system components during a conversation with TechCrunch. The design relies on a laser to compress a fuel target, but uses fewer laser beams than some inertial-confinement designs.
A Smaller Design and More Experiments
The system uses two main lasers to initiate ignition. One is divided into several beamlines that send light in concentric rings toward a flat, circular fuel target, in a sequence that begins on the outside and moves inward. The first ring starts a pressure wave moving toward the center, while the subsequent rings reinforce that wave at the appropriate moment.
When the shock wave reaches the target’s center, another laser fires a pulse that generates heat and a magnetic field. According to Kai, the design can generate high pressures using relatively low laser power, an idea that evolved from research in MIT’s Keith Nelson laboratory on studying materials under extreme conditions.
Kai believes the unit’s small size will accelerate experiments and modifications; the company aims to conduct between 50 and 80 experiments or pulses per day. The resulting data will feed simulations that use artificial intelligence to improve the design.
Funding and an Expansion Plan
Cambridge Heavy Industries recently raised $6.2 million in a seed funding round led by Azolla Ventures, with participation from Overlay, Neta Foundation, P3A, MassCEC, and the Rothrock family.
Over roughly a decade, the company plans to develop a power plant based on this concept. The plant would be larger than the current desktop model, but smaller than some other fusion facilities; Kai estimates its size at about two basketball courts. The central test will be whether the design can produce enough energy to support a practical power plant.
Tritium as an Early Commercial Path
Before reaching power generation, the company plans to use its smaller devices to produce tritium, a rare isotope of hydrogen used as fuel in most fusion plants under development. It costs about $30,000 per gram, and only approximately 40 kilograms currently exist.
Each plant requires limited quantities, on the order of grams per year, but a recent study projects a shortfall of approximately 28 kilograms in 2054 if new sources do not emerge, equivalent to about $840 million at current prices. Other fusion companies are working on fuel systems that would make their reactors largely capable of meeting their own tritium needs, but developing those systems could take up to ten years.
Why Does This Matter?
The desktop prototype does not yet demonstrate a commercial ability to generate electricity, and moving from small experiments to a plant will require scaling up the design and proving its energy viability. However, the approach offers two clear development paths: accelerating data collection through a small device and attempting to address tritium scarcity as an infrastructure problem for the sector before fusion plants become widespread. Open questions remain about the system’s ability to achieve practical fusion and the economics of scaling it up.