Wiktionary
airgap
n. 1 A gap where there is a vacuum (not actually air), used to reduce power consumption in microelectronics. 2 (alternative spelling of air gap English)
Wikipedia
Airgap (microelectronics)
Airgap is an invention in microelectronic fabrication by IBM.
Usage examples of "airgap".
He could hear and see from wherever he commanded—just now, the airgap between the balloons.