Suspensions of wire helices are absorbing at microwave frequencies. Although such suspensions are chiral, this may be accidental rather than essential for absorption in coatings. Nonchiral suspensions of connected loop arrays behave similarly to suspensions of helices.
© 1992 Optical Society of America
Craig F. Bohren, Raymond Luebbers, H. Scott Langdon, and Forrest Hunsberger, "Microwave-absorbing chiral composites: Is chirality essential or accidental?," Appl. Opt. 31, 6403-6407 (1992)