Smart-knife… I love it… the Galaxy BLADE Edge
http://global.samsungtomorrow.com/galaxy-blade-edge-chefs-edition/
"[i]With Samsung’s powerful defense-grade KNOX Security, you’ll never cut yourself again. Just scan your fingerprint on the home button and the BLADE’s finger-detection mechanism will be activated. The BLADE will retract before it cuts skin.
A human blood sensor is also available, preventing the device from being used in violent situations. Should the blade make contact with human blood, the device will automatically place an emergency call to the appropriate authorities.[/i]"