Method and apparatus for delivery of submicroliter volumes onto a substrate

A pin tool device for control and delivery of a range of volumes of fluid, comprising:

• a pin tool comprising, a solid core pin comprising a shaft, a tip and a slot at the tip;
• a pin holding block comprising side walls, an upper wall that includes one or more apertures and a bottom wall that includes one or more apertures;
• and a spring comprising a top and a bottom, which spring extends from the upper wall of the pin holding block to a point on the shaft of the pin where the bottom of the spring is attached via a spring clip,
• which slot is configured to hold a volume of fluid;
• which pin is configured to move up and down relative to the pin holding block through an aperture in the upper wall and an aperture in the lower wall;
• and
• which spring is configured to compress against the upper wall of the holding block when the pin moves upward through the aperture in the upper wall and the aperture in the lower wall of the holding block;
• and
• a controller configure to deliver at least a portion of the volume of fluid in the slot that is delivered by the pin tool by changing the speed of lowering the pin tool, thereby accurately controlling and delivering a desired volume of fluid when downward movement of the pin tool is halted.