Why MEMS Switches Are Replacing Legacy Switching Technology
Every advanced electronic system depends on one basic function.
Making and breaking an electrical connection.
That sounds simple. And for a long time it was simple enough. The relay worked. The reed relay worked. Solid state switches arrived and filled gaps the mechanical options could not. Engineers learned the tradeoffs, designed around the limitations, and built systems that performed well enough.
But something has changed.
Semiconductor devices are faster, denser, and more complex than they were ten years ago. The systems built to test them, power them, and protect them have had to keep pace. As a result, a component that was never supposed to be a bottleneck has quietly become one.
The switch.
The Two Switching Options Test Engineers Have Always Had to Choose Between
If you are designing load boards, DIB boards, probe cards, ATE systems, power distribution architectures, or high reliability switching systems, you already know the tradeoff.
On one side you have mechanical relays and reed relays. True galvanic isolation. Low conduction loss. Proven reliability over decades of production deployment. These are real advantages. Because of this, mechanical relays are still everywhere despite being a mature technology.
The problems are equally real. Mechanical relays are large and relatively slow. They are magnetic, which creates interference problems in sensitive measurement environments. Additionally, they are mechanically limited. There is a ceiling on how many switching cycles they can survive, and a floor on how small they can be made without compromising the performance properties that make them worth using.
On the other side you have solid state relays and semiconductor switches. Smaller, faster, and highly integrable. These properties make them attractive as systems get denser and faster.
However, solid state switches introduce leakage. They add capacitance and generate heat. Furthermore, their off state isolation is fundamentally limited by semiconductor physics. A reverse biased junction is not the same as an open air gap, and in precision measurement applications that difference matters enormously.
So the industry has been stuck.
Choose the mechanical option and you get strong electrical performance with density and speed constraints that get harder to live with every year. Choose the solid state option and you get the integration you need with signal integrity compromises that limit where it can be used. That tradeoff has shaped switching architectures across semiconductor test, power systems, aerospace, defense, and high reliability electronics for decades. Engineers have become expert at managing it. Nevertheless, managing a fundamental tradeoff is not the same as solving it.
Why Legacy Switching Architecture Is the Real Problem
It would be easy to frame this as a story about old technology failing to keep up. Relays are old. Solid state is newer. Eventually something newer still will replace both.
That framing, however, misses what is actually going on.
The issue is not that relays are old. Rather, the issue is that legacy switching architectures were never designed for the level of integration that modern electronics now require. Engineers built them for a different set of constraints. Larger systems, slower speeds, lower channel counts, and more available board area. They performed well within those constraints for a long time.
The constraints have changed. Consequently, the switching architectures have not changed fast enough.
What the Ideal Switch Would Look Like
Think about what an ideal switch would look like if you were designing it from scratch for the demands of modern electronics.
When off, it would be open like an air gap. True galvanic isolation with no leakage path, no capacitive coupling, and no current finding its way through when it should not be there.
When on, it would be closed like a metal conductor. Low resistance, linear signal handling, no distortion, and no thermal load from conduction loss.
Moreover, it would be small enough to support the channel densities that modern test and power architectures require. Fast enough for the switching speeds that modern systems demand. And reliable enough to survive production environments without becoming the maintenance burden that limits system uptime.
That switch does not exist in the mechanical relay category. It does not exist in the solid state category. Until recently, it has not existed anywhere.
A Silicon MEMS Switch Built for Where Electronics Is Going
Cenfire is developing a silicon MEMS switch designed to close that gap.
The core idea is straightforward even if the engineering behind it is not. When the switch is off, the device provides true galvanic isolation. A physical gap, not a semiconductor junction approximating one. When the switch is on, it creates a metallic conductive path. Actual metal to metal contact, with the resistance and linearity properties that come from that.
That combination of physical isolation when off and metallic conduction when on is what mechanical relays have always delivered. What Cenfire adds is silicon scale manufacturing.
CMOS compatible fabrication means the density, repeatability, and cost trajectory of a semiconductor process applied to a switching device that behaves like a mechanical relay. As a result, engineers get higher channel density than relay architectures can approach, faster switching than mechanical devices can achieve, and a manufacturing foundation that scales.
That last point matters more than it might seem. Legacy relays are discrete and mechanical, making them difficult to integrate with modern electronics at scale. Each relay is a separate component with its own footprint, driver requirements, and qualification burden. Consequently, scaling a relay matrix to higher channel counts means more components, more board area, and more complexity. It does not get easier as it gets bigger.
CMOS changed the world not simply because transistors were better than vacuum tubes. More importantly, it changed the world because the manufacturing process enabled repeatability, density, integration, and cost reduction that compounded over time. Every generation of the process made the devices smaller, faster, cheaper, and more capable.
Cenfire brings that same scaling logic to galvanic switching. Moving galvanic switching into a silicon MEMS architecture creates a path toward wafer level manufacturing, higher density, tighter integration with surrounding electronics, and future functionality like embedded drivers, sensing, and protection that discrete mechanical relays can never support.
The Industry Is Ready for a New Class of MEMS Switch
Modern electronics have evolved dramatically. The devices being tested are faster, the systems they power are denser, and the requirements placed on every component are more demanding than they have ever been.
The switch has not kept pace.
Mechanical relays are running into density and speed ceilings that get harder to work around as systems advance. Similarly, solid state switches are hitting isolation and leakage floors that precision applications cannot tolerate. Together, the workarounds that have managed these limitations are adding complexity, cost, and constraint to architectures that are already operating near their limits.
The next generation of electronics needs a switch that was actually designed for it.
That is what Cenfire is building.
If your system is running into switching density, leakage, isolation, relay lifetime, or thermal constraints, contact the Cenfire team at cenfire.com.
