The engineers at Ford have developed a unique way to stop a thief from stealing your alloy wheels by using a new form of biometric identification when manufacturing locking wheel nuts.

As Ford explains, working with 3D printing metal and polymers expert EOS, the car company is 3D printing locking wheel nuts with unique indentation pattern. It's achieved by recording a one-second sample of the driver's voice, saving it as a soundwave, and converting it into a pattern. That pattern is then turned into a circle, which forms the design of the locking nut indentation and the key to fit it.

3D additive printing is what makes the per-vehicle wheel nuts possible, but it isn't limited to relying on a driver's voice to create a unique pattern. Another example given is the outline of a driver's favorite racetrack, or the driver's initials as a basis for the pattern.

As a secondary security measure, Ford also ensured that the ribs inside the nut are unevenly spaced making it very hard for a copy to be produced. The indentations also widen as they get deeper, which makes it impossible for a wax imprint to be taken. The only way to produce a copy of the key and lock is to go back to Ford, look up the driver's unique pattern, and 3D print a new part.

3D printing of such small parts shouldn't take too long, and driver's shouldn't be worried about the durability of the nuts as each one is manufactured using acid and corrosion resistant stainless steel. The only frustration will come from losing the key, but not realizing you have until your car has a flat.

Ford is increasingly embracing 3D printing for vehicle manufacturing. Since 2017 the company has been experimenting with 3D-printed automotive parts. Recycling is also a focus and late last year a partnership with McDonald's allowed for coffee chaff to be turned into car parts.