What if you combine this NanoTube Sheet
Coalescence of Beta Irradiated Carbon Nanotubes (sorry for the full article you have to pay but the summary is enough to get the mind moving) Or any number of other similar articles I have seen.
How about if you use electron streams from multiple angles so that the incidence beta radiation level is only high enough for covalent bonding in specific controlled points (or lines or planes[planes would be hard])
Stack the sheets and bond them?
Join Sheets edges?
Encase determined impurities?
Alter electrical characteristics in specific patterns?
How uniform are the sheets?
How much does tube damage degrade the Van Der Waals forces?
Can that degradation be overcome by increasing interbonding due to covalent interlinks?
Space Ribbon here we come.