NOVELTY - The micro cold spray direct-write system comprises a deposition head (12), a carrier gas supply line coupled to an input of the deposition head, and an accelerator gas supply line coupled to the deposition head. The carrier gas supply line is configured to carry aerosolized precursor material comprising solid particles. The accelerator gas supply line is configured to carry an accelerator gas to the deposition head. The deposition head comprises a nozzle (14) placed at an output of the deposition head. The nozzle has an entrance opening and an exit opening.    USE - The micro cold spray direct-write system is useful for depositing an aerosolized powder of solid metallic particles on a substrate for printed circuit applications (all claimed), microelectronics interconnects, solar cell applications and embedded sensor applications.    ADVANTAGE - The micro cold spray direct-write system is capable of depositing the metallic line on the rigid and flexible substrate in an economical manner without the need of sintering or post processing even at low temperature and any shrinkage.    DETAILED DESCRIPTION - The micro cold spray direct-write system comprises a deposition head (12), a carrier gas supply line coupled to an input of the deposition head, and an accelerator gas supply line coupled to the deposition head. The carrier gas supply line is configured to carry aerosolized precursor material comprising solid particles. The accelerator gas supply line is configured to carry an accelerator gas to the deposition head. The deposition head comprises a nozzle (14) placed at an output of the deposition head. The nozzle has an entrance opening and an exit opening. The accelerator gas is configured to drive the carrier gas out of the exit opening of the nozzle as a high velocity aerosol beam such that the solid particles deform to generate a finite feature on a substrate (18). The deposition head comprises a first channel configured to deliver the carrier gas from the input along a length of the deposition head. The first channel has an exit port that is spaced apart from the entrance opening of the nozzle to form a gap between the exit port and the entrance opening of the nozzle. The deposition head further comprises a second channel configured to deliver the accelerator gas to the gap integrating with the carrier gas. The particles comprise a metallic composition. The finite feature comprises a conductive feature on the substrate. The feature comprises a line having a width of 10-50 mu m. The aerosol beam at the exit opening has a velocity of 200-1000 m/s. The first channel is positioned concentric with the nozzle. The second channel is configured to deliver the accelerator gas into the gap at an angle with respect to the carrier gas, and forms a conical channel leading into the gap. The exit port of the first channel terminates at an apex of the conical channel. The nozzle comprises a tapered converging bore leading from the entrance opening of the nozzle. The entrance opening of the nozzle has a diameter that is larger than that of the exit opening. The tapered converging bore is followed by a constant diameter bore leading to the exit opening of the nozzle. A diameter of the aerosol beam is significantly smaller than the diameter of the exit opening of the bore. The aerosol beam is collimated as it exits the exit opening of the nozzle. The aerosol beam is shaped in the bore prior exiting the exit opening of the nozzle. The system further comprises a heating element arranged adjacent to the first and second channels. The heating element is configured to heat the carrier and accelerator gas at a predetermined temperature to compensate for a drop in temperature of carrier and accelerator gas as accelerated by the nozzle. INDEPENDENT CLAIMS are included for:    (1) a micro cold spray direct-write deposition head; and    (2) a method for depositing an aerosolized powder of solid metallic particles on a substrate for printed circuit applications.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a micro cold spray direct-write system.    Deposition head (12)    Nozzle (14)    Substrate (18)    Proximal input end (23)    Pressure gauge. (26)