Cut Static by 90% Just by Changing Your Comb: The Science of Perfect Hair and the Triboelectric Series.
I’m Ken Kuwako, a science trainer. Every day is an experiment.
On a cold winter morning, you run a comb through your hair—only to have it puff up and refuse to settle. Ever sighed, “Static again”? That everyday annoyance actually has a lot to do with the material of your comb. And interestingly, the answer was already hidden in tools people used back in the Edo period.
Why plastic combs cause static electricity
When you run a plastic comb (like polyethylene) through your hair, static electricity builds up and your hair won’t stay in place. The key lies in something called the triboelectric series. This is essentially a ranking of materials based on how easily they gain a positive or negative charge when rubbed together.
According to this series, human hair tends to become positively charged, while polyethylene tends to become negatively charged. So when the two come into contact, electrons transfer easily, leaving your hair positively charged.
Since strands of hair now carry the same positive charge, they repel each other—because like charges push each other away. That’s what makes your hair spread out and go fluffy.
Edo-period wisdom helped prevent static
So how can we reduce static? The answer turns out to be something people have used since the Edo period: natural bristle brushes (such as boar hair).
Natural bristles sit close to human hair in the triboelectric series. In other words, they have similar charging tendencies, so there’s less electron transfer when they rub together—meaning less static. Even without knowing the physics, people in the Edo period discovered through experience that natural brushes were gentler on hair. It’s a fascinating case where traditional wisdom aligns perfectly with modern science.
A TV experiment shows over 10× difference
A Japanese TV program, “Tokoro-san no Megaten!” (Nippon TV), compared static electricity generated by brushing hair about 20 times with three different types of brushes. Here are the results:
- Natural bristle brush: +0.45 kV
- Anti-static brush: +0.82 kV
- Plastic brush: +5.28 kV
Tokoro-san no Megaten! (Nippon TV)
That’s more than a tenfold difference between natural and plastic brushes. For reference, the familiar “zap” of static discharge in air starts at around 3 kV. That means plastic brushes can build up charges close to that threshold—no wonder winter shocks are so common.
Static electricity can also damage your hair
Static doesn’t just make your hair look messy. It may also affect its health. The cuticle—the protective outer layer of each strand—can become damaged more easily, leading to dryness and loss of shine (the exact mechanism isn’t fully clear to me, so if you know more, I’d love to hear it).
Considering how often we brush our hair, the material of your brush is more important than it might seem.
Static electricity is often dismissed as just a winter nuisance, but behind it are real physical principles: the triboelectric series, charge repulsion, and electrical discharge. When you start seeing everyday inconveniences through the lens of science, the world becomes a little more interesting.
I actually bought a static electricity meter myself and ran some experiments. Here are the results comparing different types of brushes:
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５月のイチオシ実験！
キーンと冷えるドライアイス！気温が上がってくるこの時期・ドライアイスを使った昇華・凝結・等速度直線運動の実験はいかが？
液体ゼロ！ドライアイスが消えるまでの３時間を科学する（昇華・凝結・等速度直線運動）
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