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