Self cleaning tribological coated tobacco and herb grinders

A grinder to grind dry plant material comprising:

• a top lid portion and a first bottom portion wherein the top lid portion is slidably interfaced with the first bottom portion to form a grinding compartment;
• the grinding compartment having interior surfaces, wherein interior surfaces come in contact with the plant material during operation of the grinder;
• the top lid portion having an upper plate and a plurality of knives extending therefrom into the grinding compartment, the surfaces of which are included in the interior surfaces;
• and
• the first bottom portion having a lower plate with a plurality of knives extending therefrom into the grinding compartment, the surfaces of which are included in the interior surfaces;
• wherein the interior surfaces have a surface texture in the range of 100-250 microns;
• wherein the interior surfaces have an omniphobic coating, other than polytetrafluoroethylene, having a coefficient of friction in the range of 0.20 to 0.37 against various dried plant materials;
• and
• the omniphobic coating having a contact angle for both water and oil of greater than 90°;
• and
• wherein the lower plate plurality of knives, the upper plate plurality of knives, the lower plate and the upper plate are coated with the same coating as one another.