In exemplary embodiments, the capillary channel may be formed in {TAIL ~ the substrate} or may be a capillary tube embedded in {HEAD ~ the substrate} 
In exemplary embodiments , the capillary channel may be formed in { TAIL ~ the substrate } or may be a capillary tube embedded in { HEAD ~ the substrate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD