The second driver circuit drives a second load element formed of {HEAD ~ the second material} based on {TAIL ~ the second bias voltage} 
The second driver circuit drives a second load element formed of { HEAD ~ the second material } based on { TAIL ~ the second bias voltage }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL