More than hot air? Inside a Supersonic hair dryer.

Take 100 engineers, 600 prototypes, 100 patents pending and half a billion rand in motor technology, and you get a hair dryer from the future, writes TIANA CLINE.

A heater, a motor and pushing out some airflow – making a hair dryer sounds quite simple. Yet, most of today’s technology innovation in this space seems to revolve around LCD displays and Nano ionizers. And then James Dyson put forward a challenge: How quiet could Dyson’s team of engineers make a hair dryer?

About 1600 kilometres of hair testing later, the Dyson Supersonic has hit South African shores (and tresses).

“Hair dryers haven’t changed much since the 1960s,” laughs Brett Coulton, Dyson’s Design Manager in New Product Innovation. “We were initially looking to create a super silent hair dryer, that’s how it all started. But we also wanted to make it the most powerful that we could.”

James Dyson has invested hundreds of millions of pounds in digital motors. Dyson has been making digital motors for the better part of 20 years. But it’s not about micro-scaling the architecture; the goal is to help the motors team define what they’re trying to get out of a product.

The V9 is Dyson’s smallest digital motor to date, specifically built for the Supersonic. Every millimetre counts.

“When we started, the motor was 40ml in diameter and now we’re down to 28.6ml. The whole purpose was to push for the motor to get into the handle. All the light weight components are at the top. The motor is both smaller and lighter than conventional hair dryer motors, which are top-heavy- which also makes the hair dryer heavier on the arm. We were constantly trying to push for the diameter to be reduced, which is why, now, our motor is the size it is. It all fits into the Supersonic’s handle, which feels comfortable in most hands.”

Brett Coulton, Dyson’s Design Manager in New Product Innovation

The V9 spins at 110 000 revolutions a minute, generating high pressure air. That’s five times faster than a Formula One engine (and yes, we’re still talking about a hair dryer here). It’s also six times faster than a conventional hair dryer, at one inaudible frequency, yet is a third of the weight.

“The good thing about high pressure air is that you can squeeze it into really small spaces,” says Coulton. “It’s an incredibly dense and compact design and the high-pressure motor allows us to push air into an annulus, based on our air multiplier technology. The extra pressure on one end allows the motor to be smaller in the handle.”

The flow has been designed to be as concentrated and laminar or consistent as possible – it comes out at a 20-degree angle. Inside the Supersonic’s head, you’ll find a heater and thermistor. The thermistor – essentially a tiny glass bead – is connected to a microprocessor. The two, through wires which run down the handle, measure exit temperature 20 times every second, and report it straight to the microprocessor.

“No matter how you restrict the flow, the Supersonic manages to keep a constant temperature. We know from testing that, if you exceed 150 degrees, you start getting irreversible damage to hair. With thermistor technology, that’s never going to happen.”

Most hair dryers don’t offer this level of control. But then again, the creation of Dyson’s Supersonic took 100 engineers, 600 prototypes, 100 patents pending (16 on the attachments themselves) and half a billion rand in motor technology.

“Four years ago, Supersonic was double-handled. We found that the digital motor was spinning so fast that, if you had a silencer at either end, you could keep it very quiet. That said, it wasn’t nice to use and it didn’t look great,” recalls Coulton.

“We started from scratch and some of the things we did to make it quiet was changing the motor. We could give the same level of performance using 11 blades, but we added two extra blades, which takes the frequency that the motor produces to an inaudible range of the human ear.”

Unsurprisingly, Dyson has a semi anechoic chamber – an echo-less, sound proof area – at their lab. They set the product up in the middle to test the hair dryer and pick points in the design which are noisier. The Supersonic has 25 bits of foam strategically placed inside the handle.

“Every little bit counts! A rubber mount takes away any form of vibration or noise from the motor. Tiny little rubber pips mean there is minimal contact with the motor and casing.”

The Dyson Supersonic is the result of a $65 million investment in the science of hair: during the development, Dyson engineers studied hair from root to tip, understanding how it reacts to stresses, how to keep it healthy and how to style it.

“We’ve got laboratories that just deal with how we look at hair, we’ve got electron microscopes, tensile testing machines.. it’s been a real learning curve, but a good one.”

* Tiana Cline is a freelance content writer, technology journalist and digital strategist. She likes cats, data science, long-form and violent video games.