Extruded structure with equilibrium shape
View Patent ↗An extrusion head is disposed over a substrate, and material is extruded through an oblique (e.g., semi-circular or tapered) outlet orifice of the extrusion head to form an associated extruded structure having an equilibrium shape that resists settling after being deposited on the substrate. The extrusion head includes fluidic channels having a flat surface formed by a flat first (e.g., metal) sheet, and an oblique (e.g., substantially semi-cylindrical) surface formed by elongated oblique trenches that are etched or otherwise formed in a second sheet. The fluidic channel communicates with the outlet orifice, which has a flat edge formed by the first sheet, and an oblique edge formed by an end of the oblique trench. The material is extruded through the outlet orifice such that its flat lower surface contacts the substrate, and its oblique upper surface faces away from the substrate. Two materials are co-extruded to form high aspect-ratio gridlines.
1. A micro extrusion apparatus for producing an extruded structure having an equilibrium shape on a substrate, the micro extrusion apparatus comprising:
an extrusion head including:
a first sheet having a first surface and a first side edge;
a second sheet having a second surface and a second side edge,
wherein the second sheet is mounted on the first sheet such that a flat portion of the second surface abuts the first surface, and
wherein the second surface of the second sheet defines an elongated trench extending from the second side edge and having a concave oblique surface, thereby forming a fluidic channel having an outlet orifice including a straight first edge defined by the first sheet, and an oblique second edge defined by the elongated trench; and
means for moving the extrusion head relative to the substrate while forcing material through the fluidic channel such that material is extruded from the outlet orifice and forms an associated extruded structure on the substrate, wherein the extruded structure has a flat lower surface that is formed by the straight first edge of the orifice and is in contact with the substrate, and an upper surface that is formed by the oblique second edge of the outlet orifice and faces away from the substrate,
wherein the fluidic channel comprises a three-channel cavity including a central channel and opposing first and second side channels, wherein the central channel comprises the elongated trench, and the first and second side channels comprise second and third elongated trenches, and wherein the central channel and the first and second side channels communicate with the outlet orifice, and
wherein the apparatus further comprises means for injecting functional material into the central channel of the three-channel cavity while injecting support material into the first and second side channels of said three-channel cavity such that said functional material extruded from the outlet orifice forms an associated high aspect-ratio functional structure of said extruded structure, and said support material extruded from the outlet orifice forms associated first and second support material portions respectively disposed on opposing sides of said associated functional structure,
wherein the first sheet defines a first and second inlet ports respectively communicating with the first and second side channels of the three-channel cavity, and the extrusion head further comprises a third sheet having a third inlet port communicating with the central channel of the three-channel cavity,
wherein said means for injecting the functional material and the support material comprises means for forcing the functional material through the third inlet port into the central channel while forcing the support material through the first and second inlet ports into the first and second side channels, respectively,
wherein the second sheet further defines an inlet opening disposed in the elongated trench and extending entirely through the second sheet, and
wherein said means for injecting the functional material includes means for forcing the functional material through both the third inlet port and the inlet opening into the central channel.
2. The apparatus of claim 1 , further comprising at least one of means for heating the extrusion materials before extrusion, means for cooling the substrate during extrusion, and means for curing the extruded material.
3. The micro extrusion system according to claim 1 , wherein the first and second sheets comprise metal plates.