This child-safe fan called “TouchStop“ from SANYO will automatically stop when the metallic fan grill is being touched by hand.
Although this fan equips with touch-sensor, it unmistakably looks and works the same as any typical household fan. However, this small auto-stop modification deals with a very common child behavior of playing with an operating fan. Parents are always trying to educate their kids not to play with fan, but I doubt that any kid would listen to the warning and hold their curiosity. (There are studies about EQ of children, including this interesting TEDtalk “Don’t eat the marshmallow yet“)
So instead of forcing kids NOT to play with potentially dangerous items, why don’t we modify the design to adapt to human behavior?
Interestingly, next to it is another solution created by Dyson (http://www.dyson.co.jp/fans/) which eliminates the propeller all together, making it impossible to hurt the curious young ones. They call it The Dyson Air Multiplier:
See the Sanyo TouchStop fan in action: