Device and materials fabrication and patterning via shaped slot electrode control of direct electrostatic powder deposition

A method of fabricating an object, the method comprising:

• a) causing the formation of a cloud of charged powder having single electrical polarity and proximate to an electrode comprising at least one shaped slot, the electrode disposed between the cloud and a conductive substrate positioned to receive a portion of the charged powder;
• b) applying a first bias voltage of a polarity opposite the polarity of the charged powder to the conductive substrate to cause movement of a portion of the charged powder of the single electrical polarity from the cloud through the at least one shaped slot of the electrode to the substrate;
• c) applying a second bias voltage of between zero and a non-zero voltage of the same single polarity as the charged powder to the electrode;
• and
• d) varying the magnitude of one of the first and second bias voltages, thereby causing variation in the rate of movement of the portion of the charged powder from the cloud through the at least one shaped slot to the substrate while forming a first part of the object on the substrate.