With the technology to produce a 400-mph wind capable of drying a person’s hands in 12 seconds, the next step was to design a shell. Starting with cardboard and foam models, the team devised the shape as a waist-high, wall-mounted scoop into which users dip their hands to activate the sensor then slowly raise them while the air wicks away wetness.
Dyson’s aerodynamics specialists optimized the design for laminar flow—–the streamlined movement of air. Held inside the hand dryer’s outer gray casing, the laminar flow chamber carries the air from the motor up the nozzle and out the 0.3-mm slot, resulting in a shape that resembles a science-fiction robot’s underwear.
Engineers made more than 200 prototypes, refining the shape and functionality along the way with an unlimited budget. “The air nozzle parts for just one machine cost $13,050,” Churchill recalls. One contributing factor: “We made them out of bluestone, a material used by Formula One teams, because of the tolerance and heat-resistance requirements,” he says.
That wasn’t the only pricey part. Two selective laser sintering (SLS) machines were constantly humming, laser-bonding nylon powder, as fine as baby powder, into 0.15-mm layers, at a cost of $35 per pound of powder.