“Can it service itself?”

Self-Service: Make an object serve itself by performing auxiliary helpful functions.

Ruminating on the problem

Large installations of solar panels are commonly arranged in fields, not atop buildings. One challenge is vegetation growing between the panels causing shade and making inspection and service of the panels more difficult. One solution that is self-servicing is to introduce grazing animals, typically sheep, that will eat the vegetation with almost no need for minding.

Are you gelling?

Gel insoles and seats take the shape of person using them automatically, without the need for prior tailoring.

Roman concrete

The ancient Romans used a form of concrete that was self-healing. Thanks to the volcanic ash incorporated, crystals are formed as cracks open, resulting in concrete structures that have lasted almost two thousand years.

Space technology

Rocket engines are at risk of being weakened by the heat of combustion and destroyed by their internal pressures. The Saturn V rocket engines routed fuel around their combustion chambers and nozzles to provide cooling.

Reentry capsules like the Apollo command module used a round-bottomed bell shape that would naturally orient itself with its heat shield down during reentry due to aerodynamic forces.

Oiled bearings

Oilite bearings are formed from powdered metals and have oil injected into their porous structure using vacuum. The end result is a bearing that self-lubricates. This is analogous to the self-basting turkey which is injected with butter.


Drum brakes employ a self-adjusting mechanism to ensure that the shoes stay in close proximity to the drum even as they wear.

Knock off wheels (like the one pictured) employ a single nut at the centre of the rim to hold the wheel to the axle. These nuts are threaded so that the motion of the car tends to tighten them automatically. The threads are oriented one way on the driver’s side and the other way on the passenger side.

Self-sealing tires have adhesives within that fill voids caused by punctures and cure in the presence of air.

Tapped out

Self tapping screws drill into material and tap the hole all in one motion to fasten securely.

More examples

As I stumble across real world examples of this Inventive Principle in action I add them here.

Your turn

What problems do you face that this inventive principle could help solve? Have you used this principle before?

Photo credit https://commons.wikimedia.org/wiki/File:Bentley_hub.jpg