Micro-machined 150 A relay targets the slow step in hybrid DC breakers

What is the announcement

On October 7, 2026, Atomic Machines announced PrimeSwitch PS-150, a bistable electromechanical relay designed as the metal contact in hybrid circuit breakers for 800 V DC AI data centers. Atomic Machines says PS-150 is made on the Matter Compiler, its new micro-machine manufacturing system, which builds multi-material parts with features down to single-digit microns from design files, without masks or hard tooling.^[1][2] The New York Times reports the system's 13 automated machines build and test components, while engineers move parts between machines and help assemble the final device.^[3] PS-150 is rated 150 A continuous with 200 µΩ on-resistance and opens to 1,500 V galvanic isolation in 50 µs, Atomic Machines says; it is sampling to early-access customers.^[1][4]

Why it matters

NVIDIA's 2026 800 VDC white paper credits solid-state circuit breakers (SSCBs) and hybrid breakers with ultra-fast DC clearing. For 125 A branches in initial systems NVIDIA accepts molded-case circuit breakers (MCCBs), though clearing in up to about 20 ms needs feed redundancy or extra hold-up time, and expects SSCBs to take over.^[5]

In a December 2025 paper, Siemens and NVIDIA engineers put SSCB interruption below 0.5 ms, at the cost of conduction heat, and hybrid breakers, which conduct through metal and interrupt with a parallel semiconductor, at 1 to 3 ms, because the semiconductor waits until the contact opens far enough not to break down.^[6]

PS-150 is aimed at that wait. If the 50 µs figure holds, a hybrid could approach SSCB interruption times with what Atomic Machines calls a small bypass, provided fault current rises slowly enough.^[1][6] Atomic Machines' 2024 patent application, written for smart breakers in building load centers, describes a MEMS relay about 10 mm across that opens in 50 µs or less, noting that a MOSFET bypass's conduction energy grows with the cube of opening time when fault current rises linearly.^[7]

A comparable surface-mount part, rated on different terms, is Menlo Micro's MM9200 MEMS switch: 10 A, 300 V minimum breakdown, 6 mΩ typical and 10 µs maximum switching time, in a preliminary brief. Menlo said in 2024 its U.S. Navy breaker would pair the MM9200 with a solid-state switch, and in March 2026 reported a 1,000 V, 500 A panel of four 1,000 V, 125 A modules.^[8][9][10]

An Atomic Machines patent on a MEMS power relay, which does not name PS-150, describes a magnetically latching laminated actuator moving a crossbar across two 200 µm gaps in sealed nitrogen, with liquid-metal contacts tested below 100 µΩ.^[11]

A breaker built around PS-150 still needs fault detection, a pulse driver, the semiconductor and its energy absorber, and a series isolating contact, because the semiconductor leaks when off.^[6][7]

Technical specifications: PrimeSwitch PS-150

^{Sources: [1][4]; all values as stated by Atomic Machines.}

At 150 A, the stated 200 µΩ means a 30 mV drop and about 4.5 W of conduction loss (our calculation, assuming the resistance holds at full current and temperature). Before designing PS-150 in, an engineer needs its actuation drive, its endurance under fault openings and the temperature basis of its 150 A rating, which set the driver, the reliability case and the thermal design. In its 2024 patent application, Atomic Machines times opening from the open command to a gap that holds the rated voltage; if PS-150's 50 µs is timed the same way, it sets how long the bypass semiconductor must carry the rising fault current.^[4][7]

Recommended Reading: Power Architecture for AI Data Centers: The Shift Toward HVDC Distribution. Why rack power approaching 1 MW pushes distribution from 48 VDC to 800 VDC or ±400 VDC, with the current and busbar-loss arithmetic behind the shift.

References

1. Atomic Machines Emerges from Stealth with $250 Million to Launch the Matter Compiler, an AI-Native Manufacturing System That Builds Micro-Machines from Code, Business Wire, October 7, 2026 (company press release)
2. The Matter Compiler, Atomic Machines, accessed October 7, 2026 (company web page)
3. The startup that wants to build ‘microrobots’ with AI, The New York Times (Cade Metz), republished by The Star, October 8, 2026
4. PrimeSwitch, Atomic Machines, accessed October 7, 2026 (product page)
5. 800 VDC Architecture: Industry Alignment & Execution, NVIDIA, 2026 (white paper)
6. Protections for Data Centers Powered by Direct Current, Siemens Industry, December 2025 (technical paper by Siemens and NVIDIA engineers)
7. US20240396324A1: Hybrid digitally controlled circuit breaker utilizing MEMS relay, Atomic Machines (applicant), published by the USPTO, November 28, 2024 (patent application)
8. MM9200 Power Switch, preliminary product brief v6.6, Menlo Microsystems, undated
9. Menlo Microsystems Awarded Defense Innovation Unit Contract to Develop Advanced Circuit Breakers for Defense Systems, Menlo Microsystems, August 6, 2024 (company press release)
10. Menlo Micro Achieves Key Milestone in U.S. Navy Advanced Circuit Breaker Program, Validating Scalable MEMS Power Switching Leadership, Menlo Microsystems, March 23, 2026 (company press release)
11. US12469659B2: Microelectromechanical systems power relay, Atomic Machines (assignee), granted November 11, 2025 (US patent)