Navy Nuclear Fleet Gets Super-Fast, Super-Silent Circuit Breakers

Menlo Micro, a micro-electromechanical systems (MEMS) developer, has partnered with the Department of Defense to develop a high-current circuit breaker for the Navy’s nuclear-powered fleet. 

What is micro-electromechanical systems (MEMS) technology? Video used courtesy of Menlo Micro

The upgrade project, funded through a Defense Innovation Unit contract, will improve power distribution across the Navy’s warships, submarines, and facilities. Menlo Micro plans to supply a hybrid architecture based on its Ideal Switch MEMS technology, allowing naval electrical systems to switch up to 1 kV/10 kA. The California-based company will also assemble and test 100 A power systems for integration into future circuit breakers for the Department of Defense. 

Ideal Switch boasts significant weight, size, and cost reductions in defense, aerospace, factory, building, and renewable power distribution applications. It can also interrupt circuits ten times faster than conventional mechanical breakers. 

Menlo Micro’s Ideal Switch MEMS technology will be used in circuit breakers for Navy defense systems. Image used courtesy of Menlo Micro

Combining Electromechanical and Solid-State Tech

Menlo Micro’s Ideal Switch builds on the longstanding advantages of solid-state and electromechanical relays. 

Both offer pros and cons. Electromechanical switches have high power, low losses, and air-gap isolation, yet they’re also bulky, slow, and degrade easily due to resistance at the contact points. Solid-state switches are small, light, and fast but can struggle with leakage when handling high currents or radio frequency signals. They also usually require heavy heat sinks. 

Menlo Micro’s Ideal Switch solution borrows strengths from each technology, offering high power and speed, low losses, and a silent and vibration-proof design with air-gap isolation. With negligible resistance, the system can operate without heat sinks—a major benefit for weight-limited naval fleets. 

Menlo Micro’s Ideal Switch design. Image used courtesy of Menlo Micro

Menlo Micro will build a naval power-switching solution based on its MM9200 Ideal Switch product, integrated with a solid-state switch. The company markets MM9200 as a replacement for electromechanical relays and solid-state switches like IGBTs and MOSFETs. It’s intended for control applications prioritizing size, weight, efficiency, and thermal management. 

MM9200 launched in 2022 as the market’s highest-power MEMS switch, handling 10 A in a tiny surface-mount package. The 10 A-rated switch includes several compelling specifications, with a low on-state resistance (8 mΩ), a high voltage standoff (300 V), and a fast switching time (10 μs). Ideal Switch, made with Menlo Micro’s proprietary alloys, can operate 10 million cycles over its lifetime, 100 times longer than typical electromechanical relays. 

MM9200’s DC and AC specifications. Image used courtesy of Menlo Micro

Updated Power Systems for Naval Fleets

As the Department of Defense expands its global military capacity, the Navy is focused on modernizing its electrical distribution systems with more efficient and power-dense components. Five years ago, the Navy introduced a long-term power technology development roadmap to ensure its electrical infrastructure could meet the increasing energy demands needed in its ships and weapons systems. Legacy power systems previously lacked the inertia to handle the ramp-up/-down and pulsation effects common in complex power profiles. 

For its part, Menlo Micro’s hybrid Ideal Switch represents some of the latest advancements in circuit breaker technology, allowing naval fleets to carry a high voltage and current in a small form factor. 

MM9200 on evaluation kit boards. Image used courtesy of Menlo Micro

By eliminating external cooling and heat sink systems, Menlo Micro’s cell design can support hot-switch solutions up to five times smaller and four times lighter than legacy mechanical switches. It’s also more reliable, with a fivefold reduction in surge current.