Alignment of multicomponent microfabricated structures

Abstract

Multilayered microfluidic devices include structures that are used to align elements that make up the devices. Such elements include additional substrate layers, external sampling elements, and the like. In one embodiment, a multilayered microfluidic device includes first and second substrate layers attached one to the other, each substrate layer having a notch in an edge of the substrate layer. The notches are positioned such that they circumscribe a single opening into which an alignment key is inserted. In a method of fabricating a multilayered microfluidic device, notches are provided in first and second substrate layers, the notches circumscribing a single opening when the substrate layers are mated together. An alignment key is inserted into the single opening, and the substrate layers are bonded together. The alignment key may be, for example, a shim or a capillary element.

1 . A method of fabricating a multilayered microfluidic device, comprising: 
 providing a first notch in an edge of a first substrate layer;    providing a second notch in an edge of a second substrate layer, the first and second notches being positioned such that the first and second notches circumscribe a single opening when the first and second substrate layers are mated in a first relative position;    inserting an alignment key into the single opening, the alignment key being configured to fit into the single opening; and    bonding the first substrate layer to the second substrate layer in the first relative position.    
     
     
         2 . The method of  claim 1 , wherein the first and second notches are rectangular.  
     
     
         3 . The method of  claim 1 , wherein one of the first substrate layer and the second substrate layer comprises a groove fabricated into a surface thereof, the groove terminating in one of the first and the second notch, and wherein the alignment key comprises a capillary element.  
     
     
         4 . The method of  claim 3 , wherein the capillary element includes a capillary channel running its length.  
     
     
         5 . The method of  claim 4 , wherein inserting the alignment key into the single opening places the capillary channel into fluid communication with the groove.  
     
     
         6 . The method of  claim 3 , wherein the capillary element is rectangular.  
     
     
         7 . The method of  claim 3 , wherein the capillary element is bent such that a portion of the capillary element is not collinear with the groove when the capillary element is inserted into the single opening.  
     
     
         8 . The method of  claim 1 , wherein the alignment key comprises a shim.  
     
     
         9 . The method of  claim 1 , wherein each notch is from about 10 μm to about 50 μm in depth.  
     
     
         10 . The method of  claim 1 , wherein each notch extends into the substrate layer up to about 2 mm.  
     
     
         11 . The method of  claim 1  wherein one of the first substrate layer and the second substrate layer comprises first and second intersecting grooves fabricated into a surface thereof, wherein the intersecting grooves form intersecting channels when the first substrate layer is bonded to the second substrate layer.  
     
     
         12 . The method of  claim 1  wherein the notches are formed using photolithographic techniques.  
     
     
         13 . A multilayered microfluidic device, comprising: 
 a first substrate layer having a first notch in an edge of the first substrate layer;    a second substrate layer attached to the first substrate layer, the second substrate layer having a second notch in an edge of the second substrate layer, the first and second notches being positioned such that the first and second notches circumscribe a single opening; and    an alignment key inserted into the single opening.    
     
     
         14 . The device of  claim 13 , wherein one of the first substrate layer and the second substrate layer comprises a groove fabricated into a surface thereof, the groove terminating in one of the first and the second notch, and wherein the alignment key comprises a capillary element having a channel in fluid communication with the groove.  
     
     
         15 . The device of  claim 14 , wherein the first and second notches and the capillary element are rectangular.  
     
     
         16 . The device of  claim 14 , wherein the capillary element is bent such that a portion of the capillary element is not collinear with the groove.  
     
     
         17 . The device of  claim 13 , wherein one of the first substrate layer and the second substrate layer comprises first and second intersecting grooves fabricated into a surface thereof.  
     
     
         18 . The device of  claim 17 , wherein one of the first substrate layer and the second substrate layer comprises first and second apertures in fluid communication with the first and second intersecting grooves.  
     
     
         19 . The device of  claim 17 , wherein at least one of the grooves terminates in one of the notches, and wherein the alignment key comprises a capillary element having a channel in fluid communication with the groove terminating in the notch.  
     
     
         20 . The device of  claim 19 , wherein the capillary element is bent such that a portion of the capillary element is not collinear with the groove terminating in the notch.