Patent ID: 7449342

Claim:
A method for dispensing a controlled mass of a solid, which comprises: (a) processing the solid into a powder with an average particle size of less than about 200 micrometers; (b) forming a powder bed with a predetermined mass and uniform height from a portion of the powder; (c) providing a grille plate with an array of holes sized so that a tube can pass through each with a small clearance; (d) holding the grille plate on top of the powder bed; (e) inserting a tube through a hole of the grille plate a controlled distance into the powder bed to obtain a plug of powder, wherein the tube has an interior that accommodates a means for ejecting materials from within the tube; (f) lifting the tube from the powder bed; (g) moving the tube over a target location; and (h) ejecting a plug of powder onto target location.