Soap Bar Odometer

A bar of soap moves a great deal over its working life and nobody has ever said by how much. The Soap Bar Odometer answers the question in metres, without changing how the soap is used.

The insert

A six-axis motion sensor is embedded in a silicone insert small enough to press into the back of any bar. The insert flexes with the bar as it is worked in the hands and records motion continuously while it is off the dish. It is food-grade silicone, rated for full immersion, and unaffected by being lathered.

Reading the distance

The dish itself does no sensing. When the bar is set back down, the insert's recorded motion transfers to the dish over Bluetooth Low Energy, and the dish relays it to the app. The app reports metres travelled for that wash, a running total for the current bar, and a lifetime figure written down at the moment a bar is used down to the insert and retired.

The first bar

The Inventor had long wondered how far a bar of soap travels and found no prior measurement of it. The first tracked bar covered 1.9 kilometres over 41 days, an average of 46 metres a day, mostly across the hands rather than the body. The insert survived the full 41 days and has since been reused across several more bars; it is rated for up to 30 before the seal is retired.

Shipping

The dish and one insert ship worldwide. A spare insert ships with a Pledge and is not sold on its own to a new backer, since it needs a dish to read it.