A common implement in most work areas. These are knives with smart matter cutting surfaces and various sensor capabilities. The basic premise is a device which will stay ever- sharp and ready to cut, but will not cut unless it is held in a living hand, nor will it cut a living being.
These devices utilize a number of different methods - the initial versions were temperature-specific, refusing to cut materials in the range of normal human body temperature (causing some recipes to be changed, once they were mandated for sole use in some polities).
Later versions utilize additional sensorium information, such as electromagnetic information, sensor readings of the manipulator wielding it, etc.. Specific versions are also in use in vec and heavily tweaked or altered clades, to take their radically different 'tell-tales' into account.
Early versions were often limited to local clades' "life-signs", be that a certain temperature, moisture content, EM flux pattern, density, and/or other indicia. This often led to difficulties as other clades came into contact with these otherwise-safe tools.
Text by John B
Initially published on 31 December 2007.