Xiaomi S700 Electric Shaver: Shaving Reimagined with Ceramic Precision

You’re leaning back in the dentist’s chair. You hear the familiar whir of tools, but your attention is caught by the sample of a modern dental crown on the counter. It’s impossibly white, smooth, and feels incredibly dense and strong. The dentist explains it’s a high-tech ceramic, designed to withstand decades of grinding force while being perfectly at home inside a human body. Now, imagine a wild thought: what if you could take that same brilliant, resilient material and forge it into the blade of a shaver? What if you could solve the age-old problem of skin irritation with a material borrowed from the forefront of medical science?

This isn’t a fantasy. It’s the core principle behind a new wave of grooming technology, embodied in devices like the Xiaomi S700 Electric Shaver. The secret to its performance isn’t just an iteration on old designs; it’s a radical rethinking of the very materials we use, starting with the part that touches your skin.

The Soul of the Blade: Forged from a Tooth’s Resilience

The heart of this shaver, its cutting edge, is made from zirconium dioxide ($ZrO_2$), or zirconia. If that name sounds familiar, it should. It’s the very same biocompatible ceramic trusted by surgeons for hip replacements and by dentists for life-like, durable crowns. Its leap into your bathroom cabinet is a masterclass in technological crossover.

The first reason is its incredible hardness. On the Mohs scale, which measures a material’s scratch resistance, steel—the stuff of traditional razor blades—clocks in at around 6.0. Zirconia, however, scores an impressive 8.5, putting it much closer to diamond (a perfect 10). This isn’t just a number; it’s the key to a better shave. A harder blade maintains its microscopic, razor-sharp edge for exponentially longer. While a steel blade begins to dull and deform after several uses, causing it to tug and pull at hairs, the ceramic edge remains pristine. It continues to slice cleanly, which is the fundamental difference between a comfortable shave and a morning of irritation.

But hardness is only half the story. Zirconia is also prized for its biocompatibility, a quality governed by stringent medical standards (like ISO 10993). It is chemically inert, meaning it won’t rust, corrode, or react with skin oils or shaving creams. This dramatically reduces the risk of allergic reactions and makes the blade surface less hospitable to bacteria. So, what does this mean for you? It means the part of the shaver doing the work is not only incredibly effective but also fundamentally kinder and cleaner for your skin, especially if it’s sensitive.

The Silent Heart: The Drone Motor in Your Bathroom

A world-class blade is useless without a worthy engine to drive it. Here again, the shaver borrows from another high-tech field: aeronautics. The quiet, steady purr from within the S700 comes from a brushless DC (BLDC) motor, a piece of engineering that shares its DNA with the motors spinning the propellers of high-performance drones.

For decades, electric shavers used brushed motors, which rely on tiny physical carbon brushes to transmit power. These brushes create friction, produce a distinctive (and often annoying) buzzing sound, generate heat, and eventually wear out. A brushless motor is a revolutionary leap. It uses magnets and electronic sensors to commute power, eliminating physical contact and friction. Think of it as the difference between a bicycle with a rusty chain and a futuristic maglev train gliding silently on a magnetic cushion.

The drone industry embraced brushless motors because they are incredibly efficient, powerful for their weight, and astonishingly reliable. These are precisely the traits you want in a shaver. The result is a device that delivers consistent, unwavering torque to power through dense stubble without bogging down, all while producing a low, pleasant hum. It’s an engine built not just for performance, but for a more peaceful morning routine and a much, much longer product life.

The Ghost in the Machine: How Your Shaver Learned to Think

So, we have a medical-grade blade and an aerospace-grade motor. The final piece of the puzzle is the brain, and it comes from the world of robotics and industrial control. Your shaver doesn’t just spin mindlessly; it thinks. It does this using a PID (Proportional-Integral-Derivative) algorithm.

That might sound intimidating, but you intuitively understand the principle. Imagine you’re a chef cooking a delicate sauce. You don’t just turn the stove to “medium” and walk away. You constantly watch the sauce, and if it starts to bubble too much, you lower the flame. If it cools, you raise it. You are the “controller” in a feedback loop. A PID algorithm is the digital version of that chef.

Its roots trace back to the 18th century, where it was invented to regulate the speed of steam engines. Today, it’s everywhere. In the S700, sensors constantly measure the resistance against the blades. When you move from your cheek to the thicker stubble on your chin, the motor feels the extra drag. Instantly, the PID algorithm commands it to supply more power to maintain a constant cutting speed. When it moves back to a less dense area, it eases off. These micro-adjustments, happening hundreds of times a second, mean the shaver intelligently adapts to the unique landscape of your face. It applies power only when needed, giving you an efficient, close shave without needlessly overpowering and irritating sensitive skin.

The Grand Design: Science in the Palm of Your Hand

These core technologies are housed in a body milled from 6000-series aluminum, an alloy of aluminum, magnesium, and silicon trusted in applications like premium bicycle frames for its ideal balance of strength, lightness, and corrosion resistance. Its IPX7 waterproof rating isn’t a marketing term; it’s a specific engineering standard (IEC 60529) guaranteeing it can survive immersion in 1 meter of water for 30 minutes, giving you the freedom to shave wet or dry and clean it effortlessly.

While the metallic body offers a premium, durable feel, it’s this kind of material choice that can lead to user feedback about it feeling slippery when wet—a classic engineering trade-off between the aesthetics of one material and the practical grip of another.

Ultimately, the next time you pick up a device like this, you’re holding more than just a shaver. You’re holding a testament to technological convergence. In your hand is a piece of a dental lab, a whisper of a drone, and the ghost of an 18th-century steam engine’s brain. The centuries-long quest for the perfect shave has led us here, to a place where the solution is found not in reinventing the blade, but in reimagining it with the most advanced, reliable, and skin-friendly materials modern science can offer. It’s a quiet, daily reminder that the most profound innovations are often the ones hiding in plain sight.