Sure, if it's
aluminum foam sold as a
sheet. (I bet the GDC didn't see that coming
....)
Or if
these guys are your sponsor, just have them cast the metal foam into an appropriate size for you to insert it, being sure to begin with a crucible of melted-down legal stock. (Until the GDC comes right out and specifies limits for modifying otherwise-unrestricted <R92> items, casting whatever you want out of aluminum—or fasteners for that matter—continues to be a viable option for the minibot. It's just like the days when the Small Parts catalogue was the only legal source for most robot components.)