Patent attributes
A co-extrusion head for forming high-aspect ratio gridline structures in a micro extrusion apparatus includes multiple sheets (e.g., metal plates) that are machined and assembled to define three-part fluidic channels having associated outlet orifice disposed along an edge surface of the head. Reference surfaces are also etched in the sheets and are aligned in a straight line that intersects output junctions of the three-channel cavities. After assembly (e.g., using high pressure bonding techniques), each reference surface is located inside a notch defined in the edge surface. The edge surface of the co-extrusion head is then trimmed (e.g., machined by wire EDM) using the reference surfaces as a precise guide, thereby producing uniform length outlet orifices with uniform flow impedance.